There may simply be no remedy for this issue. You can disable all of the wake events for S5 in BIOS Setup, but this may not stop it from happening. Since the board is long past its End-Of-Life date and since Intel has exited the Desktop Boards business, no BIOS updates will be seen. All you can do it downgrade the BIOS to the version that did not have this problem.
Sorry, that's all I can do for you,
This message was posted on behalf of Intel Corporation
Thank you very much to N. Scott Pearson for the comments provided previously.
I just wanted to confirm the above information as correct, for this case the best thing to do will be to go back to the previous BIOS version that was working without problems.
Remember that Intel does not test and validate Intel® boards on Linux; however we know that a lot of NUC owners are using it successfully on many different Linux distros.
So, at this point the best thing to do will be to access your Linux distro's website and forums for peer assistance with this issue at:
Any questions, please let me know.