This might or might not be related. Few days ago I turned on my Snapmaker and it would not warm up or reset the print head to home position first. It just just started printing. My first initial though was firmware issue. Several turn on’s and off’s later, it was still happening. Like you I also print directly from my USB key drive.
Turns out my USB key drive was corrupted. It had read errors and now I can’t even format it. So check your USB key. I’m surprised it failed this fast (only had this printer not even a month). As soon as I switched to a different USB key drive, the Snapmaker was running as usual.
Hope this is your case too, and nothing more serious with the Snapmaker.