Thanks for the confirmatory post @robman0815!
I’m relieved that I’m not the only one. As the sanitzer tool is not compatible with Vault Format 8, I had to manually work around this by making a complete copy of my encrypted vault to another location, removing the encrypted files for which there were duplicates, then mounting both vaults to two separate locations and using a tool to see which decrypted files were missing from the mounted vaults by comparison.
This was somewhat painful as a Vault Format 8 compatible tool/method to map encrypted files to decrypted paths would have been much more straightforward.
In my case, all of the duplicate IDs were from a ‘CRYPTOMATOR_RECOVERY’ directory which was made in the root of my vault.
All of the files in ‘CRYPTOMATOR_RECOVERY’ were already in my vault and decrypted successfully. Hence the duplicate IDs being reported?
It would be greatly appreciated if the Cryptomator team could respond. I have a supporter certificate and have purchased the Android app via Google Play.
Thanks very much for your help!