ePMP 1000 AP Disconnecting Subscriber Modules

I Have a fairly new epmp 1000 Ap which has been working fine for one and half months. However, in the last 48 hours, it keeps on disconnecting subcriber modules, there are  only  three sm's connected to that AP, All the SM have a signal of  between 70-75. The AP has 3.0 firmware installed, TDD mode and NAT configuration, I have not made any changes to the AP since the first configuration.

When the SM disconnect, I can still ping the AP at 0ms from the main router, I am also able to login the AP. I don't understand why all of sudden SM's have started timing out at random intervals. I have change the cable from the AP to the switch and even switched ports in the stwitch but still getting the same problem.



What disconnect reason do you see in system log on AP and SMs?

Thank you.