Solving playback issues

[starper]

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. 

[makaiguy]

@starper-

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.

• ROKU LOCATES NETWORK AND REPORTS NETWORK QUALITY BUT CANNOT CONNECT
  Some router updates have changed the router's connection settings on the 2.4 GHz wifi band from b/g/n to just g/n, causing Rokus connecting to the 2.4 GHz wifi band to lose their ability to connect to the network.
  
  Note that, of recent Roku models, non-4K Roku Express/Express+ (model numbers below 3940) and Premiere/Premiere+ (model numbers below 4620) can ONLY receive the 2.4 GHz band and are therefore affected by this.
  
  The solution is to set the router's configuration back to using b/g/n.  See "Reconfiguring Router", below.
   

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:

• Xfinity / Comcast → ( https://www.xfinity.com/support/articles/change-wifi-mode-admin-tool-xfinity-xfi ) with a walkthrough ( https://community.roku.com/t5/Network-Wireless-Wired-Connections/Error-014-30-stuck-for-three-days/m...)
  
  
• Cox → (https://www.cox.com/residential/support/managing-your-in-home-network-with-my-wifi.html)
  
  
• AT&T → (https://www.att.com/support/article/u-verse-high-speed-internet/KM1046172). You can select your appropriate router from the drop down menu.

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.