I have the same problem in my Dell e7440 and my docking station Dell Pr02x
If my Laptop its open (laptop lid) the mic (Headphone whit mic on jack 3,5mm) works fine in Teams, but if I close the lid, the mic of jack 3.5mm its disabled and the only mic that works is the Laptop Mic and sounds bad.
the only solution was disable the audio and mic of my laptop, and only use de audio and mic of my Dock, so my headphone is pluged in audio jack, and i bought a mic and its plugued in the jack mic