Cambium PTP Backhaul force 300-25 RSL drops!

Hello All,

               I'm Clement from Nigeria. I installed cambium force 300 PTP baukhaul radio for a P2P link a months ago. I left the signal strenght on -63dbm and after few weeks the quality of signal degrads to -71dbm without the radio loosing alignment. Pls,what could be the cause of this?Although the link still works well but im concern about the RSL and it might still degrad more further. Thanks!

Klem - What is the distance of the link and what did Link Planner show for the recieved power for the link?