I have seen this with my ASR boards.
IMO, you are probably seeing the BIOS detecting a setting it is not happy with, and it will then put you right back to the BIOS so you can fix the setting. Of course you don't get any clue what the problem is, but that is how it works. I've had this happen to me several times.
Try loading default settings in the BIOS, and then set your minimal required BIOS settings, like RAID if you are using that, choice of graphics, boot order, whatever. Then see if that boots.
You can always check if your drives are being detected with the System Brower feature, as well as in Storage Configuration.