I have 2 PC's on the network, and one of them said 'Port scan detected' and then the 2 pc's could not longer see/access files on the other pc.
I made sure on BOTH pc's under 'Firewall' that Network Type is Home/Office, Stealth: OFF, Generic ON - which had been working fine.
I have Intrusion Detection off, and Ransomeware off.
The homegroup (Windows 10) shows both pc's connected correctly to the homegroup, so that's not the problem.
I've rebooted router and both pc's and that doesn't help.