The Windows box is my employer's laptop and it's locked down tighter than a nun's knickers. I can't install or run anything on it. Is Wireshark a Windows app or will it run on the Mac? I have to do all my network admin from the Mac.
---------- Post added at 15:33 ---------- Previous post was at 15:32 ----------
... meantime I have rebooted and switched to a wired connection, then successfully accessed the router. As I said, it only fails sometimes so nothing proven yet.
Guess switching to Safari is the way to go.