Thanks for the replies.
Fast boot was enable, so I disabled it.
Hyperkit mode was already disabled.
M.2 Link Mode was already GEN3.
Unfortunately, this did not help. It's still goes to X1 sometimes.
I may have to get my hands on another M.2 SSD somehow to test.
When first booting and then going straight into bios, does the drive show up under the M.2 configuration option? If it does not, there is a compatibility issue with the drive and the board.