Files on external drive no longer showing up in library

[Barbie-qu]

Just recently musicbee stopped listing the majority of my music in my library, and only a few locally stored tracks are shown. The majority of my files are stored on a NAS.

The symptoms seem quite similar to this post: https://getmusicbee.com/forum/index.php?topic=8452.0
Rescanning the files does change anything, and when I checked a folder in the computer browser, the 'send to music library' option is greyed out.
The NAS drive is definitely accessible.
However, there are several entries in the error log (File->Help->Support) saying: 'Thread was being aborted'. referring to two of my monitored folders.

I also tried the patch from the post I linked above, but it didn't fix the issue.

Any ideas?

Edit: I posted too soon. My music is visible again in my library, so I guess that patch did fix the issue, and it just took a while to index the 17K tracks.

[Barbie-qu]

Following up on my original post, the missing library entries problem has happened again. None of my music stored on my NAS is visible in the library.
My files on the NAS all accessible, nothing has changed in that respect since this happened a couple of days ago.

I tried patching with the patch linked from my first post, but that didn't fix anything.
I also checked the error log, and there is nothing from today.

Any ideas?

[Barbie-qu]

MusicBee has now added my entire NAS library to the Inbox. The main library is still empty.