You must not have understood my post. The problem occurs when I try to connect the 5Ghz ROKU to any of the new 5Ghz public hotspots. I can only stay connected if it's an older 2.4Ghz public hotspot. The modems aren't mine to reboot as they area PUBLIC hotspots. The problem is the ROKU.
What you need is a new cable that goes from the stick to the power adapter. I think it's called the wifi extender cable. I jumped through all these other hoops for weeks until Roku sent me this cable. Fixed everything instantly. You have to pair the remote again.
I simply upgraded my Roku and now it runs fine.