[OnePlus 3 & 3T Cross Device Development] Mustkeg:
Thank you for your idea.

Never heard of that one. The only module I'm running is AirAudio.

I pulled a logcat after rebooting:

OnePlus3T:/ $ logcat | grep NFC
06-21 21:00:15.908 4059 4059 I NfcService: Starting NFC service
06-21 21:00:15.948 4059 4059 I : [0621/210015.947915:INFO:NfcJniUtil.cpp(66)] NFC Service: loading nci JNI
06-21 21:00:15.949 4059 4059 I com.android.nf: ConfigFile - [NFC_DEBUG_ENABLED] = 0x01
06-21 21:00:15.958 553 553 D NxpExtns: find found NXP_NFC_DEV_NODE=/dev/nq-nci
06-21 21:00:16.389 4059 4212 D NfcService: NFC is on. Doing normal stuff
06-21 21:00:16.389 4059 4212 I NfcService: Enabling NFC
06-21 21:00:16.404 4059 4212 I NfcService: Enabling NFC timeout90000
06-21 21:00:16.406 4059 4212 I : [0621/210016.406869:INFO:NativeNfcManager.cpp(2358)] nfcManager_doInitialize: MW Version: NFC_NCIHALx_AR40.9.3.0
06-21 21:00:16.408 4059 4212 I libnfc_nci: [INFO:gki_ulinux.cc(215)] GKI_create_task func=0x0x7465a06134 id=4 name=NFCA_TASK stack=0x0x0 stackSize=0
06-21 21:00:16.408 4059 4212 I libnfc_nci: [INFO:gki_ulinux.cc(286)] Leaving GKI_create_task 0x7465a06134 4 74649544f0 NFCA_TASK 0x0 0
06-21 21:00:16.408 4059 4212 I libnfc_nci: [INFO:gki_ulinux.cc(215)] GKI_create_task func=0x0x7465a062b0 id=0 name=NFCA_THREAD stack=0x0x0 stackSize=0
06-21 21:00:16.408 4059 4212 I libnfc_nci: [INFO:gki_ulinux.cc(286)] Leaving GKI_create_task 0x7465a062b0 0 74648564f0 NFCA_THREAD 0x0 0
06-21 21:00:16.426 4059 4221 I libnfc_nci: [INFO:gki_ulinux.cc(215)] GKI_create_task func=0x0x74659de25c id=3 name=NFC_TASK stack=0x0x0 stackSize=0
06-21 21:00:16.426 4059 4221 I libnfc_nci: [INFO:gki_ulinux.cc(286)] Leaving GKI_create_task 0x74659de25c 3 74647584f0 NFC_TASK 0x0 0
06-21 21:00:16.427 4059 4220 I libnfc_nci: [INFO:NfcAdaptation.cc(597)] NfcAdaptation::NFCA_TASK: enter
06-21 21:00:16.435 4059 4224 I libnfc_nci: [INFO:nfc_task.cc(417)] NFC_TASK started.
06-21 21:00:16.436 4059 4224 I libnfc_nci: [INFO:nfc_main.cc(792)] NFC_Enable ()
06-21 21:00:16.438 553 553 D NxpExtns: find found NXP_NFC_DEV_NODE=/dev/nq-nci
06-21 21:00:16.438 4059 4224 I libnfc_nci: [INFO:nfc_main.cc(673)] nfc_main_hal_cback event: HAL_NFC_OPEN_CPLT_EVT(0x0), status=1
06-21 21:00:16.440 4059 4224 I libnfc_nci: [INFO:nfa_dm_act.cc(297)] NFC_ENABLE_REVT(0x5000)
06-21 21:00:16.474 4059 4212 I libnfc_nci: [INFO:gki_ulinux.cc(350)] task NFCA_TASK dead
06-21 21:00:16.476 4059 4212 I libnfc_nci: [INFO:gki_ulinux.cc(350)] task NFC_TASK dead
06-21 21:00:16.477 4059 4212 I com.android.nf: ConfigFile - [NFC_DEBUG_ENABLED] = 0x01
06-21 21:00:16.479 4059 4220 I libnfc_nci: [INFO:NfcAdaptation.cc(599)] NfcAdaptation::NFCA_TASK: exit
06-21 21:00:16.485 553 553 D NxpExtns: find found NXP_NFC_DEV_NODE=/dev/nq-nci
06-21 21:00:16.489 4059 4212 I libnfc_nci: [INFO:NfcAdaptation.cc(224)] HAL_NFC_GET_NXP_CONFIG ioctl return value = -1
06-21 21:00:16.489 4059 4212 W NfcService: Error enabling NFC
06-21 21:01:41.572 2409 4842 I ActivityManager: START u0 {act=android.settings.NFC_SETTINGS flg=0x14000000 cmp=com.android.settings/.Settings$ConnectedDeviceDashboardActivity} from uid 10044

Then again, after manually trying to toggle the NFC function via the Connection preferences:

06-21 21:01:51.009 4059 11426 I NfcService: Enabling NFC
06-21 21:01:51.015 4059 11426 I NfcService: Enabling NFC timeout90000
06-21 21:01:51.018 4059 11426 I libnfc_nci: [INFO:nfa_dm_api.cc(1528)] 0x3:NFC MW Major Version:
06-21 21:01:51.018 4059 11426 I libnfc_nci: [INFO:nfa_dm_api.cc(1529)] 0x0:NFC MW Minor Version:
06-21 21:01:51.018 4059 11426 I libnfc_nci: [INFO:NativeNfcManager.cpp(2358)] nfcManager_doInitialize: MW Version: NFC_NCIHALx_AR40.9.3.0
06-21 21:01:51.020 4059 11426 I libnfc_nci: [INFO:gki_ulinux.cc(215)] GKI_create_task func=0x0x7465a06134 id=4 name=NFCA_TASK stack=0x0x0 stackSize=0
06-21 21:01:51.020 4059 11426 I libnfc_nci: [INFO:gki_ulinux.cc(286)] Leaving GKI_create_task 0x7465a06134 4 7463ef94f0 NFCA_TASK 0x0 0
06-21 21:01:51.020 4059 11426 I libnfc_nci: [INFO:gki_ulinux.cc(215)] GKI_create_task func=0x0x7465a062b0 id=0 name=NFCA_THREAD stack=0x0x0 stackSize=0
06-21 21:01:51.021 4059 11426 I libnfc_nci: [INFO:gki_ulinux.cc(286)] Leaving GKI_create_task 0x7465a062b0 0 7463dfb4f0 NFCA_THREAD 0x0 0
06-21 21:01:51.022 4059 11429 I libnfc_nci: [INFO:gki_ulinux.cc(215)] GKI_create_task func=0x0x74659de25c id=3 name=NFC_TASK stack=0x0x0 stackSize=0
06-21 21:01:51.022 4059 11429 I libnfc_nci: [INFO:gki_ulinux.cc(286)] Leaving GKI_create_task 0x74659de25c 3 7463cfd4f0 NFC_TASK 0x0 0
06-21 21:01:51.022 4059 11428 I libnfc_nci: [INFO:NfcAdaptation.cc(597)] NfcAdaptation::NFCA_TASK: enter
06-21 21:01:51.023 4059 11430 I libnfc_nci: [INFO:nfc_task.cc(417)] NFC_TASK started.
06-21 21:01:51.025 4059 11430 I libnfc_nci: [INFO:nfc_main.cc(792)] NFC_Enable ()
06-21 21:01:51.027 553 553 D NxpExtns: find found NXP_NFC_DEV_NODE=/dev/nq-nci
06-21 21:01:51.030 4059 11430 I libnfc_nci: [INFO:nfc_main.cc(673)] nfc_main_hal_cback event: HAL_NFC_OPEN_CPLT_EVT(0x0), status=1
06-21 21:01:51.030 4059 11430 I libnfc_nci: [INFO:nfa_dm_act.cc(297)] NFC_ENABLE_REVT(0x5000)
06-21 21:01:51.076 4059 11426 I libnfc_nci: [INFO:gki_ulinux.cc(350)] task NFCA_TASK dead
06-21 21:01:51.079 4059 11426 I libnfc_nci: [INFO:gki_ulinux.cc(350)] task NFC_TASK dead
06-21 21:01:51.080 4059 11426 I com.android.nf: ConfigFile - [NFC_DEBUG_ENABLED] = 0x01
06-21 21:01:51.090 4059 11428 I libnfc_nci: [INFO:NfcAdaptation.cc(599)] NfcAdaptation::NFCA_TASK: exit
06-21 21:01:51.097 553 553 D NxpExtns: find found NXP_NFC_DEV_NODE=/dev/nq-nci
06-21 21:01:51.098 4059 11426 I libnfc_nci: [INFO:NfcAdaptation.cc(224)] HAL_NFC_GET_NXP_CONFIG ioctl return value = -1
06-21 21:01:51.098 4059 11426 W NfcService: Error enabling NFC

This was with a "| grep NFC" filter. Maybe this helps in addressing the issue? I'd be glad to pull more logs if needed.