No of the distros I tried (Debian 9 - not a surprise, Debian 9 testing - slightly suprising, Antergos - I had hoped this would) seems to support bluetooth device of the Nuc. The furthest I got was on Antergos as I could (after installing bluez and bluez-utils) turn bluetooth on and the scan discovered the device, but then pairing was not possible as the app asked me to enter a pin it suggested and then crashed; on the command line using bluetoothctl gave me a Logitech K810 prompt, but then again I could not pair. Under Debian I did not even get the OS recognize the bluetooth device correctly. Can anyone please help? Is there some firmware package I can/need to download from somewhere? Do I need to download driver code somewhere and maybe compile it? Or is my keyboard just not supported?
My NUC model (NUC7i5BNH) is different from yours and I never tried any bluetooth devices on my computer. In first I installed Ubuntu 16.04 and, currently, I am running Ubuntu 18.04.
However there are some reports on bluetooth support in newest Ubuntu versions: