I switched back to ver 11.1 because of stability, i tried lowering intensity, clock and increase voltage but no success.
the interesting point was the crashed gpus (390) did not work normal even after windows restart, they were hashing around 40 sols where other gpus did 380.
so i was forced to uninstall and reinstall gpu in device manager.
You didn't try reducing the voltage and clock.
Try reducing your power tune to -10%, -20%, -50%. Start GPUZ and monitor the min/max GPU supply voltage. If this helps then the problem is your power supply.