I recall there used to be an option where you could stop a Roku ramping up it's WiFi output to more than that of the WiFi router channel it was connected to under Wireless Secret menu but that option seems to have been removed from the 3810EU-GB model I have. I just wondered if this option might be available elsewhere? I love the stick as far as satisying an avid streamer goes but the WiFi interference it introduces into my network is a real pain.
Other than trying other wireless channels in your router on the corresponding 2.4ghz or 5ghz bands, and lowering the channel width/bandwidth, no real way to eliminate the interference that may be caused by the wi-fi direct of the remote.
You could perhaps try using one of the Roku streaming players (rather than the streaming stick), and then use an IR remote rather than the RF/wifi remotes, but I think with some network tweaking with both band selection and wireless channel selection, you can minimize the interference to a tolerable level.
You may need to consider if it is the Roku actually causing the interference, or is the Roku amplifying interference from another nearby device. May only occur when using the Roku device, but is actually being caused because the two devices are not playing nice with each other on the network. Sometimes takes a concerted effort to investigate and then place certain devices on certain bands (either 2.4 or 5ghz) and reserving an address in the router so they stay there and won't conflict with each other.
Roku Community Streaming Expert Just another Roku user... I am not a Roku employee. Insignia RokuTV, Ultra 4660, Premiere+ 3921, Express 4k+ 3941, Streambar 9102