Many thanks, but such edited screenshots are already there!
In Remote Device always shows "Syncing" - #4 by syncthem
It looks exactly the same, just the numbers are different now, of course - 121 items with ~3.36 MB and “Syncing (99%, 3.36 MiB)”.
The version number of syncthing changed and of course the total amount of files.
But otherwise, it is exactly the same as before!
But now we don’t see a “revert” button on the remote site and I don’t see a “override changes” button on the local site (at least not on the regular Syncthing webpage where Devices and Folders are listed).
Hopefully, the remote site can locate the logfile and give some insight into the problems that Syncthing sees. I don’t know when I will get a reply.