Please read my OP(s) again. It was the Bluetooth failure that lead me to try Miracast instead. Then, Miracast appeared to have an IP address conflict, and I discovered I could not find a way to log into my router (likely because it is behind a switch.)
I am pretty dumb on this stuff, but I am WELL aware Bluetooth and Miracast are separate and distinct systems, and Bluetooth does not utilize WiFi.
I have also stated the WiFi on the laptop was otherwise working fine.
Looking back through your replies it looks to me like you had a power surge or a partial equipment failure that created the hot mess. If you haven’t done so, I would power everything down for a few minutes.