Well, that fix didn’t last long. I’m utterly perplexed by this. I’ve reset windows firewall rules on the remote pc which worked. For a while. The workgroup vanished again from my main rig. 🙁 . I’ve looked more closely at my main rig and have uninstalled Comodo firewall and gone back to using Windows firewall again. This seems to have cured things. For the moment anyway.