After completely wiping Joplin from my Mint 22 system, I've installed a brand new Joplin 3.1.20. Looks good. The sync target (~/Joplin) is fully populated with all my 321 notes plus resources. Also looking good. But Joplin is completely empty. What could I do to make Joplin see these notes? I've tried the options in Synchronization/Advanced settings but still can't see my notes.
I should mention that I'm setting up Syncthing, which is working fine on two Android devices.
If both sides report that synchronisation has completed, yet you cannot see some (or all) of the notes, then I think you may have been hit by the bug https://github.com/laurent22/joplin/issues/6517 (especially since file system sync is involved).
Are you sure the folder is actually synchronised between the two devices with Syncthing? If yes, then please also make sure that you're using the right path in the Joplin configuration for the filesystem sync target. At the moment, it just looks as if the sync folder was simply empty.
Thank you, tomasz86, for your thought. Yes, the devices are definitely syncing - a sample file placed in one device appears in the other. And the Joplin folder definitely contains all my stuff - see photo: