Hello,
I've got the same problem on my 3 devices : windows pc, macOS and iOS. Synchonisation failed due to supposedly files deleted from OneDrive...
But no files concerning Enpass was deleted...
A tempoary fix is to kill EnPass and restart it. Then the synchronisation can be done.
But the problem reapears soonafter...
I was tired of this, buggy OneDrive Sync so I move to GDrive Sync, and it seems there is no problems anymore... Let's see on the long run...
But after abaondonning iCloud Sync because of the iCloud Sync keep expiring problem, I have to abandon OneDrive...
Let's hope there will be no problem like this with Gdrive...
If this is the case, I'll have to move to another application's passwords.