Pokemon Sword and Shield is causing Roku devices on the same network to crash and enter into a boot loop. As players work their way through Pokemon Sword and Shield, some have noticed that their Roku devices have suddenly started to crash and restart improperly. At first, the issue was blamed on Roku's most recent update, but it turns out that the issue is caused by Pokemon Sword and Shield's impact on network traffic. The crash is due to a combination of Pokemon Sword and Shield's Y-Comm service, which continuously searches for other players on the same wireless network or online, and the Roku devices inability to tell Pokemon's data apart from data it needs to function.
According to a post made on Reddit about the issue, the issue seems to be because Pokemon Sword and Shield's network probe looks similar to data packets used by Roku, to the point where the Roku device can't tell it apart and then crashes due to its inability to read it.
The issue seems to mainly affect Roku sticks and not other Roku devices. There's also an easy enough fix - players who aren't using online features can simply place their Nintendo Switch in Airplane Mode, which causes the Switch to stop continuously spamming Pokemon Sword and Shield data. Roku is also aware of the issue, so we can hope that Roku releases a fix for the problem soon. If your Roku does crash, simply close Pokemon Sword and Shield and then reboot the Roku stick by unplugging it and waiting 30 seconds.
As someone impacted by this issue, I can honestly say that this was one of the most randomly frustrating things I've ever experienced. I tried EVERYTHING to fix my Roku's incessant crash issues over the last two weeks before learning that it was tied to the new Pokemon game of all things.