Problem with ONU terminal Bdcom p1004b

Greetings. Need help with ONU terminal Bdcom P1004B.

A couple of months ago, after a power outage, there was a strange problem with the "terminal". When connected to the socket, the "Power" light starts flashing (does not glow constantly green, as it should be during normal operation, namely blinking), the other indicators do not show any signs. Turning the device off and on, as well as disconnecting all wires except power, does not help in any way to fix the problem. But, after some time of connecting to the outlet, after 2 - 10 hours, the "terminal" starts to work normally, that is, "power" starts to glow green, and not blink, and the rest of the indicators start, after which the Internet connection naturally returns.

If after that you disconnect the device from the outlet for 5 - 10 seconds, then when you connect it back, the "terminal" connects without any problems and works properly for weeks. But it is worth disconnecting the device for an hour on the floor, as the above problem repeats again (4 times in several months the terminal was disconnected from electricity for a long time and the same problem repeated every time).

What could be the reason for this strange behavior and is it possible to somehow try to fix it?