I have the ASUS Wi-Fi6 mesh router as well. I decided to try one last thing before ordering a node to plug it in to.
I separated my 2.4/5GHz networks and gave them different SSIDs. Seems to be working momentarily, whereas in the past I couldn’t even get it to connect any longer without a direct Ethernet line.
I’ll report back in a couple of days.
This did not help. It lost connection within an hour and never reconnected as of this morning.