CRS125-24G-1S losing configuration

The CRS125 is restarting by itself and losing configuration. I don’t know exactly when it loses the configuration, when I see the ip went back to 192.168.88.1. I’ve updated the firmware of routerboard, but it didn’t help. It started after upgrading from a very old version to current versions. Before it worked normally.

/system routerboard print
       routerboard: yes
             model: CRS125-24G-1S
     serial-number: ...
     firmware-type: ar9344
  factory-firmware: 3.12
  current-firmware: 6.49.6
  upgrade-firmware: 6.49.6

What I have to do to resolve it?

try directly netinstall, if not solve, the nand is out…