So I was getting on the Roku this morning to watch my show, but then it said I wasn't connected to the internet anymore, went to reconnect and not a single network is popping up, I tried resetting, restarting, diagnostics screen, nothing is working, I tested it out with my hotspot and the hotspot worked but it's the only one that is popping up so I'm not sure why no other network is popping up right now, how do I fix this?
There are some router setting issues that can prevent establishing Roku wifi connections. And to make matters worse, some of them can be caused by recently-reported router updates. These have primarily been reported with routers supplied by internet providers (Comcast/Xfinity, Cox, and AT&T so far), but it's possible they could also occur with other internet providers or user-owned routers that have received similar updates.
Reconfiguring Router
Thanks to forum user @AvsGunnar@AvsGunnar for providing the links below to instructions for reconfiguring router settings for the listed internet suppliers. If you can't do this yourself, you may need to contact your internet provider to make these changes for you:
If your problem was not caused by any of the above, often a restart of the router (even if other devices are still connecting) followed by a restart of the Roku will allow the connection to be reestablished. Depending on your Roku model and Roku version number you'll find the "System restart" option under either "Settings > System > Power" or "Settings > System", or if more convenient you can just remove the Roku's power for a few seconds and let it restart.