Your experience has taught me a little (re: UPnP.) Windows is not my primary OS and only use it for testing.
Sometimes a reboot can help. That's as long as it does not affect anything else you are doing on the computer.
Is port forwarding out of the question? Just a suggestion.
I always port forward my p2p apps because it's far more reliable for long sessions.
As far as I know, Windows does have a habit of resetting some security settings to default during updates (including some firewall settings.) Have you checked Windows Defender or that another security app is not blocking WireShare to the outside world? Re-check any system setting that might possibly affect WSHR.
Talk later, I'm off to bed for now.