TYT IP-98 PoC radio boot loop

For a few days, I've been struggling with a Tytera model TYT IP-98 PoC (Push to Talk over Cellular) radio that has the boot loop problem typical of the Android system. Basically the PoC turns on, but in a few seconds, it restarts randomly always with the initial logo. I searched online to see if there could be a solution perhaps, by doing a factory reset with a key combination, but in vain.