The screenshots are taken within minutes of having deleted that file “Updated 20XXXX - Copy.vsd” and the file having been re-synced from PC A to PC B.
I should add that I have been manually syncing files back from PC B to PC A for many months. Syncing back automatically has turned out too dangerous for me.
It seems that Syncthing on PC A doesn’t recognize this and thinks there are lots of different files, when actually there aren’t any – as Syncthing on PC B also reports correctly.