SXT-Lite5 reseting to factory default after boot

I have this SXT-Lite5 working for some days fine but since two days this unit eachtime when it is rebooted (warm or cold) the unit is back to factory default settings.

Anybody any clues?
Running ROS5.24 with updated firmware.

I have now some 35 SXT-Lites running and one had a one of the chains not transmitting good (10dB less than the other chain) and now this one, after two weeks (with daily power shut offs) this unit only likes to move back to his factory default status. I’ll send it RMA but has anyone similar experiances?

see this topic http://forum.mikrotik.com/t/sxt-back-to-default-configuration-after-each-reboot/64236/1
Try open you SXT

No rust on mine… RMA