I didn’t change it to AP mode or repeater after the failure. When the admin web page was accessible, I turned the 5G band off, then on a couple of times. I clicked the ‘reboot’ button once. Other times when I couldn’t access the admin web page via the 2.4G band, I pulled the power cord and re-inserted it. I didn’t try to access the admin web page from a wired connection to it at any time.

Currently, the router has been running for a few minutes more than 24 hours and the 5G band hasn’t dropped yet. When I upgraded to 3.101, I did it the same way as before. I used the ‘Online Upgrade’ tab on the Upgrade page. I can’t recall how much time elapsed between the upgrade and the first 5G band failure.

Is there a test process or procedure you want me to perform if/when it fails again?