Other ideas online failed, but this works! I was having the hardest time trying to get my Bluetooth headphones (bose 700) to work after my company updated me to Windows 11 on my Dell 5550 laptop. I manually tried updating the Intel Bluetooth and WiFi Drivers from Intel's website. that didn't help. I knew a few others seeing this problem on their own PCs as well. Our headphones would work in browsers, apps in windows 11, but not in MS Teams. We tried many other options until one fixed it... So here it is. Does this work for others as well?
I first go into Bluetooth and Devices.
Then click on View more devices.

Then scroll down and click on More Devices and Printer Settings.

Then I right click on my headphones icon and go to Properties.

Then go to the Services tab and Uncheck the Handsfree Telephony option.

After unchecking this, my headphones work in MS Teams!!