@DuelingFatty
The Roku Express is only capable of operating on 2.4ghz. The new Roku Express 4k/4k+ devices (like yours) is dual band so able to operate on either the 2.4ghz or 5ghz.
If you find that you keep losing connection on the 5ghz band, you can try using the 2.4ghz band which may give you a better/more stable connection or alternatively, instead of using "Auto" channel selection on the 5ghz, try manually assigning a channel using 36-48, or 149-161. Whenever Auto wireless channel is left enabled on the 5ghz band, there exists the possibility that the router will select a non-compatible (DFS channels 52-140) that will cause the Roku to disconnect and be unable to reconnect. Roku cannot see/use these DFS channels. Could also be just some noise/interference on this 5ghz band that the Roku is having problems with, again causing disconnection.
For your router, you should be able to make the channel change under the Advanced tab...Wireless..Wireless Settings..5ghz..
You will have to disable "Smart Connection" first if you wish to assign manual channels on the Archer A7.
Roku Community Streaming Expert
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