Are you talking about a Roku Tv scanning for local over-the-air broadcast stations, or are you talking about scanning for your WiFi networks (I'm guessing the latter)?
When seeking help it's ALWAYS a good idea to include your Roku model, model number, and Roku software version (all available via Roku menu path Settings > System > About), as different models have different capabilities and the advice you need may depend on this information.
Roku Express/Express+ (not the relatively new Express 4K/4K+) and Premiere/Premiere+ are lower end units with single band Wi-Fi radios that only support the 2.4 GHz band. They, and many other devices of all sorts that are 2.4 GHz only, can't even see the 5 GHz band, !et alone connect to it. If you have one of these Roku models and a dual band router with both 2.4 and 5 GHz bands, be sure the router's 2.4 GHz band is turned on.
Within the 2.4 GHz band, Rokus support channels 1-11 as are used in North America. If your router supports 2.4 GHz channels outside this range make sure your router is set to use a channel in this range and that you aren't using an auto setting that could select channels outside this range.
There have been reports lately of updates to the router shutting off the router's 2.4 GHz band, especially with equipment supplied by internet providers. Users have had to contact their provider to get 2.4 GHz turned back on or in some cases have the router replaced with a new one.
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
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