Is one of the antennas of this link directed east or south? If yes, is the link stopping Transport traffic in the morning between 8:00am - 10am?
I had one link in years 2003 - 2005 (5,8ghz radiolan hardware) it drives me crazy. On some days in January and February every morning the link stopped passing traffic for arround 30-60min.
In this situation always the sun was rising by best cold weather conditions.
I changed antenna to a hornantena and it helped.
We had this issuein Africa by sundown too.
So my conclusion is , it is related to sun.
Do not worry about it will go away latest end of February