USB Headset Microphone Stops Working For Phone Calls

[pone]

On a Pixel 10, right after the last Android 16 upgrade, all my bluetooth headsets stop working for phone calls. In the bluetooth settings for my Flex 800 headset, the slider for Phone Calls is GONE. I saw a Reddit thread where the user disables Google Play Services and the Phone Call slider re-appears. I confirm that does happen. But as soon as you re-enable Google Play Services, the Phone Call Slider disappears again. Whenever I receive a call, no one can hear my voice while using the Flex 800.

It looks like the last Android 16 update broke something. Is anyone else seeing this problem and is there a workaround?