I would need more information about your system configuration. Do you have the operating system on the M.2 or SATA drive? You mentioned a CD-ROM and it is connected to the monitor, isn’t it? Which operating system are you using?
Please verify the BIOS version and drivers on your NUC. The latest BIOS version is 0350.
This link contains the latest drivers and BIOS of the Intel® NUC Kit 5i7RYH
Downloads for Intel® NUC Kit NUC5i7RYH