RB711GA-5HnD drops suddenly to 6Mbs

I have two PTP links using RB711GA-5HnD on each end. Using dual chain NV2 and both train up at 300/300 with roughly -56dBm signal strength running RoS 6.5.

Have worked flawless for 6+ months. During the last month or so, they have suddenly been prone to dropping to 6Mbs and staying there until I forcibly drop and re-establish the connection. Some times they will fluctuate between 6Mbs and 27Mbs, but they never go above 27Mbs until I either drop and re-establish the connection or reboot one of the units. They then are rock solid at 300/300 for about 24 to 36 hours before they again drop down. I have tried several different versions of RoS with no difference. CCQ is fine and changing frequencies doesn’t seem to make any difference.

I have tried using custom configured data rates and disallowing any MCS less than 4, but behavior remains the same.

Has anyone else had similar problems or have any suggestions?

Thanks

Welcome to the club → it is know issue. But no solution there :frowning:

http://forum.mikrotik.com/t/nv2-locked-to-6-5mbit-known-issue/70355/1