Yep, I also use my excellent WF-1000XM4 for MS Team call in my office.
As said before, this is due to the Speak detection feature that turn off your headphone volume and enable ambient noise when it detects that you are talking (assuming that you want to hear the person next to your, outside the headphone, hence ambient noise on and volume down).
While doing a video call, you don't want that and do need to hear the person in the headphone and not the one next to you outside the headphone...
To go around this, you can simply use the mobile app and disable it manually.
BETTER still (and this is Sony's genius!), you can use the app so that your headphone automatically configure themself according to your location -> "In location A, apply Sound profile A". Pure genius!
I configured my office as a location in the app and set up the profile for the speak detection feature turned off and noise cancelling on. This way, as soon as i put a foot in my office building the feature is disabled and I can use my headset for Team calls as expected.
As soon as I am out and on my way home (public transport etc), the headphone reconfigure themselves automatically with the Speak feature back on etc...
This is such a great feature !!!
