Precision 5560 and USB headset

I have a laptop user with one of the high performance PRECISION 5560 laptops. She is using the high performance dock, correct for this laptop. She has a USB headset. The headset works on all other devices, laptops, tablets and PCs, audio in and out. So this is not a headset issue.

Here's the issue:

Her headset, she can hear everything fine. Teams, videos, audio.. All work fine. However, nobody can hear her at all, Teams, even Microsoft voice recorder sees no microphone on the headset (remember, the headset works perfectly on all other devices).

Here's what we have tried.

• Tried a USB camera, picture is fine, can be seen by other parties in Teams. But the others cannot hear anything from the camera microphone. Yet, the camera also works fine on all other devices. 
• Tried a Bluetooth headset with a USB dongle, works fine. No problem with audio in or out.
• The docking station has been replaced.
• The laptop has been re-imaged recently.

In all testing, the sound settings were open to ensure microphone and speakers were at sufficient levels.

There is no rhyme or reason why this is not working perfectly.

Any other ideas?