I will be more than glad to assist you with your current concern.
I have sent a private message to you in regards to your current thread.
After an extensive research I was able to find some details that could be useful for you:
-If you were able to select EUFI boot, the system will require a fresh install of the OS. Please remember to do back of your information before the install.
-Since you have a Linux System, if the issue persist and you are not able to complete an EUFI Boot, please refer to Linux in order to get the proper steps.
At the following link, you will be able to find some steps provided by Linux in order to solve your concern: [SOLVED] UEFI-boot on Intel-NUC
Please let me know how it goes in order to further assist you if required.
I would like to know if the information provided to you was able to solve your concern?
In case if you need further assistance do not hesitate to reply back.
I am looking forward to hearing from you.