If you haven't done so, I'd suggest a factory reset and re-configure. If you've done that, I'd suggest contacting ASUS if still under warranty.
Thanks Smokindog, I had considered this and tend to use as last resort only but decided to take the plunge.
Factory default restore, initialize all settings, recreated all configs from scratch. 24 hours later cannot get to web interface, just times out before even presenting login page. Two hard resets (just to be sure) recreated all settings from scratch. A couple of glitches with web interface over first fortnight (time outs not being able to get to login page). Power recycle works again for couple of days, but has slowly gotten worse over last two weeks to the point of web interface no longer being accessible within hours of reboot, and mobile app not being able to connect advising problem with router and to reboot.
So after almost a month of testing 22525 have rolled back to 21709 which for me at least has been stable, and over last few days has remained so with no timeouts, get fast responsive performance from web UI and app, Memory utilisation sits around 58% and CPU barely moves off 1-5% range. I do not believe this to be a hardware related issue, and while not impossible, typically very small percentage of units have hardware related defects and these are typically seen regardless of firmware versions in my experience.
I have the following feedback on last two firmware versions which may lead some to ask why I apply the updates at all especially when 21709 for the most part is pretty solid. Quick answer, to take advantage of any security fixes or stability issues and remain as close to most current version as possible.
For now 21709 will remain in place until next update.
Firmware 22525
1.Fixed CVE-2022-46871
- Assessing CVE to understand how it applies to router and risk. Potentially still exposed
2.Fixed Client DOM Stored XSS.
- I use third party plugins to prevent DOM XSS vulnerabilities, so while not immune is relatively low risk.
3.Improved AiMesh backhaul stability.
- Use wired backhaul and have not experienced any backhaul stability issues across three devices.
4.Fixed AiMesh topology UI bugs.
- Unable to validate, have not observed any topology bugs.
5.Fixed the reboot issue when assigning specific clients in VPN fusion.
- Unable to validate as I don't use feature.
6.Fixed the VPN fusion bug when importing the Surfshark WireGuard conf file.
- Unable to validate as I don't use feature.
7.Fixed network map bugs.
- Haven't seen any bugs in network map so can't validate.
Firmware 22068
1. Improved system stability.
- Fail
2. Fixed the IPsec VPN compatibility issue with Win10.
- Unable to validate as I don't use feature.
3. Fixed the VPN fusion user interface issues under the HTTPS connection.
- Unable to validate as I don't use feature.
4. Fixed Client DOM Stored XSS vulnerability.
- I use third party plugins to prevent DOM XSS vulnerabilities, so while not immune is relatively low risk.
5. Improved Wireguard performance.
- Unable to validate as I don't use feature.