[Android Q&A, Help & Troubleshooting] robobub:
Very peculiar issue occurring: there are a fair amount of photos and videos that show up under google photos under library -> photos on device -> camera with SDCard Icon.

But the location for these files is "/external/video/media" or "/external/image/media" under ""On Device (size)." The other files taken in a similar way are correctly on "/storage/9C32-13OC/DCIM/Camera"

When clicking these files, they play normally, clicking share and More or Create Link says "Error, could not download media" and using Google Photos to Move / Copy says "Trouble Moving 1 item"

When ejecting the SDCard and physically removing it while keeping Google Photos open, all the files actually on /storage/<ID> disappear, and all these weird files remain and can be played. This is how I discovered it wasn't just today's videos, which were mysteriously not being uploaded to my nextcloud. No other app can see these videos/images, including the system's gallery app, and they are not in the internal emulated "SDcard"

These are on my SO's phone and I use the exact same model phone. I did discover that I do have some files like these but hey are all older than the oldest file on my SDCard, e.g. Google Photos has somehow decided to cache them. But on my SO's phone, these files are intermingled with the ones she's actually taken

Interestingly when I switch the google photos account to another google user logged on the phone, those files disappear. I did try moving files to the locked folder but it says "Trouble moving to Locked Folder. Try again later"— I did verify I could move files actually on the SDCard there, and they are then removed from all views except Locked Folder.

In this folder, on the top right when clicking the SDCard Icon, it does show the "SD Card folder" as "file:///storage/9C32-13OC/DCIM/Camera" as expected.

I searched for the filename in a file browser as well as in adb shell (using find / -name "filename" 2> /dev/null) and nothing comes up. As there are some lengthy videos in here, I used DiskUsage to see what might be using a lot of space, and the Google Photos app is using 7.55 GB of data, so it seems like they are being stored there. And it makes sense why they can't be found, as /data/data/com.google.android.apps.photos is only accessible by that app or the system, and I'm unrooted.

My SO said she took them the same way she normally takes photos and video, and of course when I take some they show up on the actual SDCard. I suppose in theory I could use adb backup and follow instructions on how to decrypt the data files, but really what the heck is going on?

We aren't on the latest phone or even the latest Google Photos app (could be a bug with this specific version, but then again google photos isn't taking the photos/videos, the system Camera app is). I could try upgrading her google photos but I also don't want to lose these videos of our kid. It does seem like it would back them up, but we don't have enough Google Storage to back them up online (hence why we use nextcloud), and they don't even show up under different google accounts as mentioned.

Phone: LG G7

Android 10

Google Photos: 6.21.0.504361003