A possible solution could be installing BIOS version 0048 on the board.
Please check the BIOS Version you have installed on the board. If the version is previous than 0048, I recommend you to update it to that BIOS version.
If it is the latest version 0051, you would need to rollback the BIOS to version 0048 through the recovery method.
I was successful with installing the 0048 bios but sadly it did not solve my problem.
Please try updating the BIOS to version 0049 and then 0051.
If you continue having the same issue, you may contact our Technical support department so you can replace your board. Contact Support
You have turned off Legacy Boot in BIOS but you boot with a Legacy graphics card?