What OS? GitHub issue also doesn’t say. Does that imply it fails on all tried (still would be helpful to know)?
Duplicati not automatically restarting after update on MacOS might be a related issue, but yours is manual.
If this is Windows, is Duplicati a Windows service (where I get an always-fails, but have ideas) or Tray Icon?
Do you ever reinstall the base version of Duplicati (as seen in About --> System info), or just do upgrades?
Is the 1 of 10 a recollection over history, or a test e.g. by using Downgrading / reverting to a lower version?