Have you tried changing the wireless router’s 5GHz channel?
While the lower frequencies go thru physical material more easily, I set mine to a higher frequency to not interfere with my ISP’s fixed wireless system.
Regarding 2.4GHz frequency…
My mom’s house is bombarded with 20+ 2.4GHz wireless signals from neighbors.
Her set up…
Wireless router - 2.4GHz (g,n); 5GHz (n) - 1st floor
Roku - 2.4GHz (n) - 1st floor
Tablo - 2.4GHz (n) - 2nd floor (HD 720 - 5Mbps)
Flat HD antenna taped to 2nd floor window - ~20 miles from broadcast towers
Everything is wireless.
Worst possible setup for stability, and performance.
It works great. 