Oddly, I'm also running Merlin but I did have a problem where my laptop thought it was connected to the AP but couldn't get local network traffic routed to it. Easiest solution turned out to be to just reconnect, so I don't actually know the deeper problem.
I don't think it has any relation, but since it's the first time it's happened, it was kind of a freaky coincidence!
Did not experience any issues with my RT-AX86U running Asuswrt-Merlin either.