5G Frequency issue on RT-AX86U after update 3004.388.8_2

[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. Been that way for years. After the update to 3004.388.8_2 5G changes to 157 one day 161 the next day and 160 one day. The configuration says 11 and 44 with auto on extension channel. Regressed to 3004.388.8 and everything stays ok, and channels stay locked to 11/9 and 44/160. Updated a second time to 3004.388.8_2 and same thing started happening. Have gone back to 3004.388.8. Any ideas? The odd thing is when this happens while on 3004.388.8_2 the Wi-Fi icon in the upper right of router interface which usually shows:

WiFi:
2.4G: 11/9
5G: 44/160
shows
WiFi:
2.4G: 11/9
5G: 157

 

[jetpack42]

I don't think that there were any wireless driver or GPL changes from 388.8 to 388.8_2. Could it be possible that your router is detecting radar since 160MHz uses DFS channels? Do your logs have any entries that say anything to that effect?