DutchNucUser, I had a similar issue on my 5425, and found this white paper by Intel, USB 3.0* Radio Frequency Interference on 2.4 GHz Devices. So, I plugged my USB2.0 keyboard and mouse receiver into a USB extension cord to move it physically away from the USB3.0 devices plugged into the NUC and haven't had a problem since.
Thank you for your suggestion:
- when I installed the NUC I needed keyboard/mouse so it was the first usb device in the usb2 front left. Later on, not sure why, this was switched to the second usb2 port, and then the problems started. I didnt relate the unintended switch to the mouse problems. First I thought it was battery problems etc. I couldn't find any solution so I changed mouse to usb2 wired. After my USB3/HD problems I switched the wireless usb2 to the original position and that made the mouse working correct again. I will keep your suggestion in mind. But this will not solve my USB3 problems.
Read the thread here about "inconsistent USB activity". I'm going to do a series of restarts and cold starts, with and without certain devices attached to the USB ports to see if there is any clue. Although all of the external ports on my NUC (5425) are USB 3.0, I only have 1 USB 3.0 device plugged in. I don't know if that affects the RFI issue discussed in the white paper or not though.