Sudden Signal problems, good RX bad TX

RouterOS Wireless Networking
1

I have a 2.4ghz hpol link running on rb600s and SR2s and the link has been running great at -60 on both sides, until today.
Now one half of the link is running at -60, and the other half of the link is bouncing between -60 and -85 in seconds.
The antennas have not moved, the pigtails are fine. I have tried swapping in brand new SR2 and have even swapped in a brand new rb600 on one end.

The side of the link that is transmitting poorly has 2 other radios in it, vpol 2.4 and 900mhz and none of those links are having issues.

I am a bit stumped on what could be causing this problem other than magical wireless gnomes or some kind of crazy interference that is only effecting the transmit of one radio (or the receive of the matching radio). Again, both sides of the link have had the cards swapped with no change.

Any ideas?

2

Further investigation reveals that the crazy signal strength fluctuation are only occurring on certain data rates.

All of the B mode data rates (1, 2, 5.5, 11) as well as 9 and 12 show wild variance in signal strength, while the higher data rates ( and 6mbps) seem to be stable.

Removing the lower data rates seems to improve stability of the signal strength