[Android Q&A, Help & Troubleshooting] tehlordvortex:
Log outputs

I ran

logcat | grep "Documents"

in a terminal emulator and got the following output:

05-20 15:23:55.198 16731 16744 D Documents: Loading roots for com.android.providers.downloads.documents with [Root{authority=com.android.providers.downloads.documents, rootId=downloads, title=Downloads}]
05-20 15:23:55.217 16731 16731 D Documents: onCreate: intent = Intent { act=android.intent.action.OPEN_DOCUMENT_TREE cmp=com.android.documentsui/.DocumentsActivity }, extra = null
05-20 15:23:55.232 16731 16731 D Documents: DocumentsActivity enter from copy
05-20 15:23:55.232 16731 16731 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:23:55.460 16731 16744 D Documents: Loading roots for com.android.externalstorage.documents with [Root{authority=com.android.externalstorage.documents, rootId=FF78-08ED, title=SD card}, Root{authority=com.android.externalstorage.documents, rootId=primary, title=Internal storage}]
05-20 15:23:55.500 16731 16744 D Documents: Loading roots for com.android.providers.media.documents with [Root{authority=com.android.providers.media.documents, rootId=images_root, title=Images}, Root{authority=com.android.providers.media.documents, rootId=videos_root, title=Videos}, Root{authority=com.android.providers.media.documents, rootId=audio_root, title=Audio}]
05-20 15:23:55.856 16731 16744 D Documents: Loading roots for com.google.android.apps.docs.storage with [Root{authority=com.google.android.apps.docs.storage, rootId=1, title=Drive}]
05-20 15:23:55.857 16731 16744 D Documents: Update found 8 roots in 757ms
05-20 15:23:55.885 16731 16753 D Documents: Loading roots for com.android.externalstorage.documents with [Root{authority=com.android.externalstorage.documents, rootId=FF78-08ED, title=SD card}, Root{authority=com.android.externalstorage.documents, rootId=primary, title=Internal storage}]
05-20 15:23:55.886 16731 16753 D Documents: Update found 8 roots in 408ms
05-20 15:23:55.892 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:23:55.935 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:27:51.522 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:27:51.547 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:27:55.805 16731 16731 D Documents: onCreate: intent = Intent { act=android.intent.action.OPEN_DOCUMENT_TREE cmp=com.android.documentsui/.DocumentsActivity }, extra = null
05-20 15:27:55.807 16731 16731 D Documents: DocumentsActivity enter from copy
05-20 15:27:55.807 16731 16731 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:27:55.821 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:29:01.191 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:29:01.211 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:29:06.285 16731 16731 D Documents: onCreate: intent = Intent { act=android.intent.action.OPEN_DOCUMENT_TREE cmp=com.android.documentsui/.DocumentsActivity }, extra = null
05-20 15:29:06.287 16731 16731 D Documents: DocumentsActivity enter from copy
05-20 15:29:06.287 16731 16731 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:29:06.302 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]

Then I also tried with another app:

05-20 15:33:27.827 16731 16731 D Documents: onCreate: intent = Intent { act=android.intent.action.OPEN_DOCUMENT_TREE cmp=com.android.documentsui/.DocumentsActivity }, extra = null
05-20 15:33:27.831 16731 16731 D Documents: DocumentsActivity enter from copy
05-20 15:33:27.831 16731 16731 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:33:27.896 16731 16731 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:34:35.746 17511 17524 D Documents: Loading roots for com.android.providers.downloads.documents with [Root{authority=com.android.providers.downloads.documents, rootId=downloads, title=Downloads}]
05-20 15:34:35.783 17511 17511 D Documents: onCreate: intent = Intent { act=android.intent.action.OPEN_DOCUMENT_TREE cmp=com.android.documentsui/.DocumentsActivity }, extra = null
05-20 15:34:35.793 17511 17511 D Documents: DocumentsActivity enter from copy
05-20 15:34:35.793 17511 17511 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:34:35.989 17511 17524 D Documents: Loading roots for com.android.externalstorage.documents with [Root{authority=com.android.externalstorage.documents, rootId=FF78-08ED, title=SD card}, Root{authority=com.android.externalstorage.documents, rootId=primary, title=Internal storage}]
05-20 15:34:36.021 17511 17524 D Documents: Loading roots for com.android.providers.media.documents with [Root{authority=com.android.providers.media.documents, rootId=images_root, title=Images}, Root{authority=com.android.providers.media.documents, rootId=videos_root, title=Videos}, Root{authority=com.android.providers.media.documents, rootId=audio_root, title=Audio}]
05-20 15:34:37.580 17511 17524 D Documents: Loading roots for com.google.android.apps.docs.storage with [Root{authority=com.google.android.apps.docs.storage, rootId=1, title=Drive}]
05-20 15:34:37.581 17511 17524 D Documents: Update found 8 roots in 1899ms
05-20 15:34:37.594 17511 17533 D Documents: Loading roots for com.android.externalstorage.documents with [Root{authority=com.android.externalstorage.documents, rootId=FF78-08ED, title=SD card}, Root{authority=com.android.externalstorage.documents, rootId=primary, title=Internal storage}]
05-20 15:34:37.594 17511 17533 D Documents: Update found 8 roots in 1601ms
05-20 15:34:37.626 17511 17511 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:34:47.615 17511 17511 D Documents: onCreate: intent = Intent { act=android.intent.action.OPEN_DOCUMENT_TREE cmp=com.android.documentsui/.DocumentsActivity }, extra = null
05-20 15:34:47.617 17511 17511 D Documents: DocumentsActivity enter from copy
05-20 15:34:47.617 17511 17511 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:34:47.636 17511 17511 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:35:04.237 17511 17511 D Documents: onCreate: intent = Intent { act=android.intent.action.GET_CONTENT typ=application/zip cmp=com.android.documentsui/.DocumentsActivity (has extras) }, extra = Bundle[{XTRA_FILTER=.zip}]
05-20 15:35:04.297 17511 17511 D Documents: DocumentsActivity enter from copy
05-20 15:35:04.298 17511 17511 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:35:04.366 17511 17511 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}, Root{authority=com.google.android.apps.docs.storage, rootId=1, title=Drive}, Root{authority=com.android.providers.downloads.documents, rootId=downloads, title=Downloads}]
05-20 15:35:04.395 17511 17511 V Documents: DirectoryFragment resume from background invalidate to refresh UI
05-20 15:35:04.738 17511 17533 D Documents: Before filtering 0, after 0
05-20 15:35:04.821 17511 17533 D Documents: Before filtering 64, after 1
05-20 15:35:04.822 17511 17533 D Documents: Found 2 of 2 recent queries done
05-20 15:35:04.828 17511 17533 V Documents: SortingCursorWrapper init 1(1) with needShowDrmMethod = 15
05-20 15:35:04.833 17511 17511 D Documents: Start load finished
05-20 15:35:08.844 17511 17511 D Documents: onFinished() [content://com.google.android.apps.docs.storage/document/acc%3D1%3Bdoc%3D18]
05-20 15:35:08.904 17511 17511 D Documents: onFinished: uri=[content://com.google.android.apps.docs.storage/document/acc%3D1%3Bdoc%3D18], data=Intent { dat=content://com.google.android.apps.docs.storage/document/acc=1;doc=18 flg=0x1 }
05-20 15:35:15.770 17511 17511 D Documents: onCreate: intent = Intent { act=android.intent.action.OPEN_DOCUMENT_TREE cmp=com.android.documentsui/.DocumentsActivity }, extra = null
05-20 15:35:15.772 17511 17511 D Documents: DocumentsActivity enter from copy
05-20 15:35:15.772 17511 17511 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:35:15.788 17511 17511 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}]
05-20 15:35:24.221 17511 17511 D Documents: onCreate: intent = Intent { act=android.intent.action.GET_CONTENT typ=application/octet-stream cmp=com.android.documentsui/.DocumentsActivity (has extras) }, extra = Bundle[{XTRA_FILTER=.img}]
05-20 15:35:24.224 17511 17511 D Documents: DocumentsActivity enter from copy
05-20 15:35:24.224 17511 17511 D Documents: DocumentsActivity onCreate Ongoing copy = 0
05-20 15:35:24.234 17511 17539 W Documents: Failed to restore stack: java.io.FileNotFoundException: Failed to find matching root for null
05-20 15:35:24.236 17511 17511 D Documents: Loading finish in RootLoader with [Root{authority=null, rootId=null, title=Recent}, Root{authority=com.google.android.apps.docs.storage, rootId=1, title=Drive}, Root{authority=com.android.providers.downloads.documents, rootId=downloads, title=Downloads}]
05-20 15:35:24.382 17511 17511 V Documents: DirectoryFragment resume from background invalidate to refresh UI
05-20 15:35:24.421 17511 17534 D Documents: Before filtering 0, after 0
05-20 15:35:24.456 17511 17540 D Documents: Before filtering 0, after 0
05-20 15:35:24.502 17511 17534 D Documents: Before filtering 64, after 0
05-20 15:35:24.502 17511 17534 D Documents: Found 2 of 2 recent queries done
05-20 15:35:24.502 17511 17534 V Documents: SortingCursorWrapper init 0(0) with needShowDrmMethod = 15
05-20 15:35:24.525 17511 17540 D Documents: Before filtering 64, after 0
05-20 15:35:24.525 17511 17540 D Documents: Found 2 of 2 recent queries done
05-20 15:35:24.525 17511 17540 V Documents: SortingCursorWrapper init 0(0) with needShowDrmMethod = 15
05-20 15:35:24.540 17511 17511 D Documents: Start load finished
05-20 15:35:26.108 17511 17511 D Documents: onStartLoading contentChanged: false, mIsLoading: false, mResult: null
05-20 15:35:26.109 17511 17511 V Documents: DirectoryFragment resume from background invalidate to refresh UI
05-20 15:35:26.109 17511 17749 D Documents: Loading directory for content://com.android.providers.downloads.documents/document/downloads/children with: userMode=0, userSortOrder=0 --> mode=0, sortOrder=2, drmLevel=-1
05-20 15:35:26.120 17511 17749 V Documents: SortingCursorWrapper init 0(0) with needShowDrmMethod = 15
05-20 15:35:26.124 17511 17749 D Documents: Loading directory finish for content://com.android.providers.downloads.documents/document/downloads/children with: userMode=0
05-20 15:35:26.141 17511 17511 D Documents: Start load finished
05-20 15:35:27.595 17511 17511 V Documents: DirectoryFragment resume from background invalidate to refresh UI
05-20 15:35:27.641 17511 17524 D Documents: Before filtering 0, after 0
05-20 15:35:27.705 17511 17524 D Documents: Before filtering 64, after 0
05-20 15:35:27.705 17511 17524 D Documents: Found 2 of 2 recent queries done
05-20 15:35:27.705 17511 17524 V Documents: SortingCursorWrapper init 0(0) with needShowDrmMethod = 15
05-20 15:35:27.709 17511 17511 D Documents: Start load finished
05-20 15:35:32.172 17511 17511 D Documents: onStartLoading contentChanged: false, mIsLoading: false, mResult: null
05-20 15:35:32.172 17511 17511 V Documents: DirectoryFragment resume from background invalidate to refresh UI
05-20 15:35:32.172 17511 17749 D Documents: Loading directory for content://com.android.providers.downloads.documents/document/downloads/children with: userMode=0, userSortOrder=0 --> mode=0, sortOrder=2, drmLevel=-1
05-20 15:35:32.184 17511 17749 V Documents: SortingCursorWrapper init 0(0) with needShowDrmMethod = 15
05-20 15:35:32.185 17511 17749 D Documents: Loading directory finish for content://com.android.providers.downloads.documents/document/downloads/children with: userMode=0
05-20 15:35:32.193 17511 17511 D Documents: Start load finished
05-20 15:35:34.569 17511 17511 V Documents: DirectoryFragment resume from background invalidate to refresh UI
05-20 15:35:34.620 17511 17534 D Documents: Before filtering 0, after 0
05-20 15:35:34.698 17511 17534 D Documents: Before filtering 64, after 0
05-20 15:35:34.698 17511 17534 D Documents: Found 2 of 2 recent queries done
05-20 15:35:34.698 17511 17534 V Documents: SortingCursorWrapper init 0(0) with needShowDrmMethod = 15
05-20 15:35:34.706 17511 17511 D Documents: Start load finished

So it seems it can detect the SD Card, Internal Storage, Drive etc just fine. But for some reason, only the "Recents" option is showing up