Puli AX (GL-XE3000) beta testing - router switches off completely after a few minutes

Hi all, I’m proud PuliAX beta tester for almost a month now. All was amazing from the beginning, but during last 10 days it switches off and that’s it. Anyone with same experience?
I have tried with many options with enabling and disabling different functions, updated firmware to latest beta version, used 3 different SIMs from 2 different countries, and so on.
To turn it back on, I have to press and hold on/off button for 10s at least twice. Usually from the second go it turns on and then it works normally for a 10 - 30 mins, more or less.