Make sure you are running the latest firmware and driver releases from the Digi web site.
Otherwise, if the unit needs repair, you will want to contact Digi Technical Support with the product serial number.
Does this issue still happen if you disconnect all USB device and the network cable, then power cycle the AWUSB/14 (with only power connected)?
Yes, the device was with latest firmware. And yes, there is no USB devices and network connected, just the power cable.
I would contact Digi support for a warranty repair