What's the model number of your Roku 2? Settings > System > About
While the actual Roku 2 models (2720 and 4210) were both dual band and are still supported by Roku, if you have an older device that contains "Roku 2" in its name (Roku 2 HD, Roku 2 XD, Roku 2 XS) those are single band devices, and are no longer supported (not getting updates).
Depending on your physical layout, there may be spots where the 2.4 GHz band doesn't function properly, if your device is actually one of those legacy devices. And, there are a slew of other things that could impact. But let's start with the model number, and the additional details as @Strega requested.
DBDukes Roku Community Streaming Expert Note: I am not a Roku employee.
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