Wifi stuff can be so persnickety. For example, I have a tablet that I use only for viewing my outdoor cameras. Today, one of the cameras was not showing up. I diagnosed for about an hour, resetting the router, the tablet, and the camera, etc. I finally realized that for some reason the tablet had connected to the router at 2.4 ghz. It usually connects at 5 ghz., the preferred.
So, I reconnected it at 5 ghz and the troublesome camera showed up. I have no idea why. The camera itself is only capable of 2.4 ghz., not that it should matter.