Sorry, this was my stupidity. For some reason after applying the 388.8_2 my 5GHz got set to Auto with Auto DFS channels. I did not catch this until doing updated for 3rd time. Now you know why the name TheOldGuy.
I updated my ASUS AX5700 (RT-AX86U) to 3004.388.8_2 from 3004.388.8 about a week ago. We noticed that our 5G connection speeds were much lower. In our neighborhood because our houses are so close we all select a channel in the hood and stay there. My 2.4 runs on 11/9 and my 5G runs on 44/160...