P3424WEB, doesn't work correctly with Microsoft Teams

Maybe the same issue?

https://www.dell.com/community/en/conversations/monitors/p3424web-macos-camera-issues/66a9edf447effa74c482dc0b

We have this problem with both the Latitude 7440 and Precision 7680.  We have several people complaining about the same issue.  It is random.  They may be 20 minutes into a Teams or Zoom call and all of a sudden their microphone stops working.  This is using USB and bluetooth speaker devices and headphones like a Jabra 510.  Flipping to internal usually works but not always.   This is a big problem.

Always include version of Windows in your posts.

Have you checked Windows power settings?  Open Device Manager and expand USB. Open each USB entry and if it has a Power Management tab, uncheck the box "Allow PC to turn off..."  Then do same for all Human Interface Devices (HID) listed in Device Manager that have a Power Management tab. 

Close Device Manager and reboot. See if that helps. If problem continues, you may have to modify the active Windows Power plan on its Advanced settings screen.

To receive assistance from Dell support agents, they need to first verify the ownership and warranty status. Click the blue "Get Help Now" on the right to start a private live chat session. Share the private P3424WEB Service Tag with them. Also list the PC model, operating system, and how the P3424WEB is connected to the PC using which ports and cables.

Verify in the P3424WEB Menu-Others that your P3424WEB is running firmware M2T103 or later.

* Open the P3424WEB Menu

* Go to Others
- Run Factory Reset
- Verify DDC/CI is On

* Go to Personalize
- Change Fast Wakeup to On

* Go to Audio & Webcam
- Verify Microphone = On
- Verify Webcam & Presence Sensor = Enable

* Exit the Menu and retest