Have you tried changing the channels for both bands?? Perhaps there is some type of interference.

I am using 5g band and tried 2.4g. I have been using 3 computers on 5g for months and not many other 5g signals around. Everything I am using is
within 20 feet of the router and only one wall between them. Signals on computers in same location (2 laptops) are very strong. I just turned the router so ROKU is broadside to the antennas instead of off the end.
I am limited to how I can adjust location of equipment.
I was hoping I could get answer like 'the roku has wifi problems'

tnx

Got it running. Moved the ROKU 3 feet and was able to connect on 2.4g. No luck on 5g. I really wanted 5g because this apartment complex has at least 40 routers on 2.4g

Cheers !