OK, all fixed.
I have a 64 bit device and it appears that the driver defaults to 32 bit location and then cannot be found by windows. Intel, please fix this.
I downloaded the driver (BT_19.10.1635_64_Win10.exe) from this location Intel® Dual Band Wireless-AC 7260 then ran the setup process and as I already had the same driver version installed I chose the REMOVE option. I rebooted then ran it again and when I got the the Typical/Custom/Complete option I chose Custom and then changed the install directory from "C:\Program Files (x86)" to "C:\Program Files\Intel", then rebooted after the install and Bluetooth started working.
Let me know if anyone else has this issue and this fix worked.
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Thank you very much for sharing the information above, it will be really helpful for all the peers viewing this thread.
It is great to hear the issue was resolved and you were able to fix the bluetooth problem and now the NUC is working properly.
Any other inquiry, do not hesitate in contact us again.