A couple of weeks ago 2 different PTP 550 links that have been fine for months started having random issues and drops. These are set up Master/Slave TDD single 40Mhz channel and are passing around 100Meg. Clean wireless channels and no GPS being used.
F=5590 11acvht40plus. Reason: 40 (STA KEEP ALIVE RX STUCK) is the log in the slave radio when it happens. About 1 to 2 minutes of downtime.
I have read some past issues but we were running 4.6.1 on these links and today I upgraded to 4.6.2 with no change. Happens on average one time per hour. Nothing fancy on the setup just a basic bridge that was working and now creating issues for customers.