station deauths

I have problems with one of my backbone stations. It deauth randomly and I cant figure out why. On AP it shows as connected with wds (dynamic), but I cant reach station behind, and have to disable and enable ap to get connected to station again.
When I then connect to station, logs says it got authentication timeout. I have 10 other locations like this, and they all work fine.

both ap and station is rb 333 3.0r4

any idea what I should look for ?

What is the signal strength?

-75 → -77, Noticed that signal to noise was only 26.

CCQ and noise floor?