I have a TerraMaster NAS (underlying OS is Linux) which has an SMB share set up.that is accessible to my Windows 11 machine. I can use Cryptomator without any problems if I have a vault on the Windows machine but as soon as I create a vault on the SMB share it initially works but starts misbehaving after a couple of days. Eventually leading to an apparently empty vault. I can repair the vault which recovers some of the data but not all. The NAS has been checked to see if anything touches the vault directory but nothing is apparent. The NAS is being used as a staging machine before the vault is copied to the cloud (but I haven’t got around to that bit yet as I wanted to check Cryptomator first). Luckily I still have backups but could have lost over 15 years of research if I depended on this alone.
I can now confirm that SMB shares from another Windows machine work fine. I have set SMB on another Linux based machine and one of the vaults does not work properly.on that machine. So it looks like there is an issue on SMB sharing from linux machines but no issues from Windows SMB shares. The NAS and the Linux machine have shown no problems with discrete files and archive files in testing via their SMB shares.
Accessing vaults on a very large capacity TruNas Scale based storage unit has shown no issues at all. So it looks like SMB shares need to be set up in a certain way on a NAS for Cryptomator to work properly. Am investigating further.