XPS 15 9550 shuts itself randomly - ASF2 FORCE OFF

Hello, My laptop starts to shuts itself randomly - it seems not connected to any work I done on it on that moment. There are no any error message, no BSOD - despite the Windows 10 settings to NOT automatically restart on error. There are no dump files as well. It is not overheating since I stress tested it - temps are never reaching 70 deg C. Only clue I have is in BIOS power events logs and it is say ASF2 FORCE OFF. I tried to google it but there is no much clues on this. Can anybody know how to solve this? THANKS!