I use the routers as access points on 2 locations. On both locations I experience issues.
I don't know the trigger, but after a while it goes haywired.
I only replied to the topic starter I also have strange issues with this version.
I have 3 of these routers and experience lockups on one of them. This one becomes unreachable after a few weeks.
This one is under light load.
The other two are under medium load and sometimes start disconnecting / reconnecting the clients every few minutes.
After a reboot it's working again...
Just tested Merlin on my RT-AX86S.
Updating (from stock firmware) went fine, but I was unable to connect to the router via WiFi.
After a power off/on I was able to connect to 2.4GHz but unable to connect to 5GHz.
Tested with my Sony Xperia phone.
Did try some settings but was not able to...