Decryptation error

Mobile Version 1.0.316
Desktop Version 178, on LInux Mint 19.3. Encryptation and history enabled.
After synchronizing I am notified (Sychronisation Status) of 2 Resources which cannot be decrypted.
I checked the ressources on the desktop: they are o.k… Netherthless I erased them in the desktop notes.
The error reappears after each synchronisation and the mobile app tries to decrypt these 2 entries again. Pressing “Retry” doesn’t help. Is there a way to erase these entries?
Best regards