Well, I just had same issue (after upgrade of all units to 5.24 + firmware upgrade).
One link full 5Ghz mimo (58dB S/N, 99% CCQ) link with 240Mbps connection rate (set) just stopped working this morning.
No more IP traffic, even no more mac traffic possible. But on both sides radios still in registration table.
Both side still show the mac of the other in the ARP table.
Just disabled - enabled one radio and the link came back up....
Logs on both ends show nothing.
I've had this on some other links before running 5.22 and 5.23 but 5.24 should have solved it........ thus not??
(On both side no bridges are involved directly, so no rstp protocol involved. I units further down the line yes... but would that have an effect on this links?)
Show your appreciation of this post by giving me Karma! Thanks.
Rudy R. Puister
WISP operator based on MT routerboard & ROS.