WiFi clients lose WAN since updating AX86U to 388.1

[Occupant]

I recently upgraded my AX86U to 388.1, making sure to do a full factory reset afterward, and since then WiFi clients have been having WAN dropouts. I can still see my LAN and reach devices on the network but I'm no longer being routed any internet. Just doing a disconnect/reconnect will fix things. My wired clients are unaffected when this happens. I looked at the logs and nothing seems to correspond to these incidents. Any ideas what's going wrong here?

 

[RMerlin]

Set a fixed channel.