Sorry, back on 380.67_0 now. Couple of restarts behind me and it seems OK. But it seemed OK last time too...If you are still on 270.26,try this plz....
Remove usb drives,reboot
Flash with 378.55 (https://www.asus.com/support/FAQ/1030651/)
Follow all steps.
Reboot
Flash with 380.67
Reboot to see if 380.67 is still there