It’s been connected to the WiFi for around 2 years now, so I know that isn’t an issue. I have a PS4 in the same room that is connected and works just fine as well. What makes this odd is that it can see my WiFi still, and even says that the connection is good, but it will not connect anymore. I’ve reset my modem, even though I know that isn’t the issue. I’ve also restarted the TV, reset the network settings, and factory reset the whole TV. It still won’t connect despite seeing my internet.
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 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.
We’re upgrading Roku Community to bring you a faster, more mobile-friendly experience. You may notice limited functionality or read-only access during this time. Read more here.
Planned Downtime:
Community will be unavailable for up to 24–48 hours during the upgrade window during the week of May 19th and you may notice reduced functionality.
In the meantime, for additional assistance, visit our Support Site.
We're sorry for this disruption — we’re excited to share what’s next!
For support, visit support.roku.com.