Even though the NUC D54250 series is discontinued, you might have an old one that wasn’t BIOS upgraded.

Intel NUC BIOS upgrade procedure:

1. Download Intel NUC BIOS. This page is sorted by date
2. Extract the IFLASH.EXE and .bio file to a USB flash drive.
3. Reboot the NUC and at the BIOS flash screen press F7
4. select the flash drive to boot from.

The Intel NUC BIOS upgrade takes 4-5 minutes.