All Roku Stick players are dual band (2.4 and 5 GHz). If your router supports both bands, you could try to force it to use one band or the other. This requires a different SSID for each band. Another place to look is the channel number used on 5 GHz. Roku devices do not support all potential channels. There is a subset of channels labeled DFS, and Roku devices don't work on them. You need to be on channel 48 or lower, or channel 149 or higher. Again, this is only on the 5 GHz band.
Most routers default to auto-channel selection, which may not choose the best channel. If someone nearby has a router on the same channel, the interference could cause what you describe. So changing the channel used can sometimes help. This applies to both 2.4 and 5 GHz.
Dan
Roku Community Streaming Expert
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