I've just switched my router from the OEM Plusnet one to a ASUS DSL-AC68U. Everything seems to connect OK but both my Hubitat Hubs are showing "Cloud Connection unavailable". The Portal works fine and I can connect to them from there and my Node Red pi is talking to them fine over the LAN. Both are on static IPs set in the DHPC server in the router (as they were on the previous router). I've checked that "Enable DoS protection" is disabled in the router as I read that might cause the issue.
Any other ideas?