If you mean this on the old UI Destination screen:
it moved up a bit on the new UI Destination screen:
It’s renamed, but I think it actually does more now…
About Duplicati → Changelog
- Improved backend test function
This isn’t really by new UI, but new UI describes new test. Old was just a file list, basically a sanity test on the connection (like you said). New one exercises files.
2025-05-29 - 2.1.0.119_canary_2025-05-29
Better backend Test
The test feature has been updated to now check for write permissions, instead of just listing the remote folder. For ngclient, the Test check now uses this extended check to inform the user if there are files in the destination folder. This shows a warning if creating a new backup pointing to a folder with existing data, and a warning if attempting to restore from a folder with no files. If the write part fails for a test during the restore flow, this is not treated as an error in ngclient.