I have two macs using syncthing and they are getting out of sync and require manual intervention.
On mac #1, I create a directory with a bunch of files in it
On mac @2, I move this directory somewhere else (but still in the synced directory) and rename it
When I go back on mac #1, it is out of sync. The failed item is the directory that was moved in its original location. The error message is “Directory not empty”
A pattern beginning with a (?d) prefix enables removal of these files if they are preventing directory deletion. This prefix should be used by any OS generated files which you are happy to be removed.