Syncthing Issues that I can't figure out..... Disk full?

[Fffrank]

I'm having an issue with syncthing but it seems to be greater than just the container.  Hoping someone may be able to help as I've been chasing my tail for a few weeks.

 

When you add a sync'd directory, it creates a folder named ".stfolder" -- my app does this correctly and syncs the directory the first time but less than 24 hours later that file is gone and the app claims the sync is broken.  This only happens to one of my media directories - I have a handful of other directories that work just fine.  It takes another 24-48 hours to re-add that directory and rescan it.  So very hard to pin-point exactly what is going wrong.

 

[KBJD3] 05:22:27 WARNING: Error on folder "Movies" (knpc2-fptgj): folder marker missing (this indicates potential data loss, search docs/forum to get information about how to proceed)
[KBJD3] 05:22:27 INFO: Failed initial scan of sendreceive folder "Movies" (knpc2-fptgj)

 

I've checked the logs and the only errors I'm seeing indicate that my appdata directory is out of space.  This definitely isn't the case (and even if my cache drive is out of space, this should roll over to my user drive -- right??)  I always have 300-400gb of free space on my cache drive and 3-5tb on my user drive.

 

KBJD3] 01:55:13 WARNING: Fatal error: 7kzp7-phzqo Update(7777777-777777N-7777777-777777N-7777777-777777N-7777777-77777Q4, [45]): write /config/index-v0.14.0.db/018042.log: no space left on device
Panic at 2021-01-06T01:55:13-06:00
panic: write /config/index-v0.14.0.db/018042.log: no space left on device

To confirm that my /config/ directory is properly mapped ->