PROBLEM:
SYSTEM MAY NOT BOOT AFTER INSTALLING FROM EXTERNAL USB MEDIA
SOLUTION:
IT IS PREFERRED THAT USB INSTALLATION BE PEFORMED USING BOOT OVERRIDE IN THE BIOS BOOT SECTION
IF THE PREFERRED BOOT ORDER IS MANUALLY CHANGED AND THE USB DEVICE IS REMOVED WITHOUT RE-ADJUSTING TO THE M.2 AS THE PRIMARY, THE SYSTEM MAY STILL BE LOOKING FOR THE USB AND ERROR OUT OR DROP BACK INTO BIOS.
RESET THE BOOT ORDER TO M.2 AFTER INSTALLATION IF THE 1ST BOOT DEVICE WAS CHANGED TO USB.