random connect to sxt lite 5

RouterOS General
1

hi
i have a sxt lite 5
i want connect to device whit winbox but only random connect.
and when connected to device i no have problem.
i mean Connects once and does not connect once.
programed the device whit Diferente version file on net install .
i replaced cable and POE adapter.
The problem is still there.

please guide me

2

The same happens when you try to connect with mac instead of IP ?

3

i cant see any ip or mac address to connect the device.
maybe on next power i can see mac or ip .this is randomly.