Note that USB 3.0 ports cause interference for connected keyboards and mouses. That is why all mainboards still ship with both USB 2.0 and USB 3.0 ports. The NUC unfortunately does not have any USB 2.0 ports. Nevertheless, you can fix it by buying a short USB extension cable to avoid the interference.
Please access the BIOS press F9 and set your system to the factory defaults, then press ten to save the changes.
Also, I’m not sure if you have updated the BIOS, the BIOS version 0348 fixes problems with USB ports you can download it at:
Once you download the BIO file you can do a BIOS recovery to that BIOS version, you can follow the steps here:
Also, if you access the device manager, do you see any exclamation marks? If not, try uninstalling the USB Serial Bus Controller and restart the system, after the system restarts they will be automatically reinstalled.
Please let me know if that can help you any better.