External device not seen [actually seen and rejected, two dings heard- one for 'device detected and immediately followed by second 'device ejected tone] on one USB port, but second port works fine. System is a XPS 12 9Q23 running Windows 10. External device is a B&N Nook ereader for ebooks.
Dell USB and External drive diagnostics find no problem.
All USB ports deleted and then detected successfully in Device Manager.
Device scan [windows] does not see device even though device is attached.
Other devices work fine on the same port that rejects Nook.
What is wrong? how to fix?
Thx for any response, Stan