Mikrotik RB493AH and RB435G strange behavior

HI.. i have strange problem.
We use on our network for AP RB435G mikrotik 5Ghz nstream 5760Mhz / 40mhz/turbo

and i am client with RB493AH mikrotik 5Ghz nstream etc..

I have problem with connection, drop every 3 min, or 15min, or 3-4h.
Others guys who connect to these AP point are stable at the same time for 10-48h
here is picture what happend when i have drop out.
rb435g AP side.png
rb493ah client.png
Or message with " lost connection, not polled for too long "


I dont understand why at AP side mikrotik say unknown device, we use mac filter only
SW 6,27 at every side
Signal is -71/-73, card power default, at ap side 15 dbi
distance 1,5km LOS ok
Today i check grid anntena at my house, all ok, no water.

anyone ?