So, here's something odd. After shutting down for the night, by the next morning, all the PCs on my network can't connect to the router any more. I need to power-cycle the router for them to be able to connect to the network again. Despite this, the Wifi works fine, and any tablet/phone in the apartment stays connected no problem. It's ONLY affecting directly connected, networked units.
Yesterday I went through a lot of resets and updates, I have a new screen when going into the router settings, and thought that would do it... Today, the same issue. This is getting ridiculously frustrating.