Hi All,
So, I have had Bose QuietComfort 35 II headphones and a Plantronics Voyager working fine with my Windows 10 set up for about 18 months. And I have to admit, when it all worked it was a dream. I have a slightly complex set up with two separate handsfree kits, a Yeti Blue microphone, Logitech Brio webcam (which also takes mic inputs) and separate Logitech speakers.
Recently experienced the same issues listed here with the Bose headset. It would allow me to use the headset, but refused to pick up the microphone. For a while, I used my USB Yeti Blue as the mic and the headset as headphones only. However, not ideal.
Having looked into this quite a bit, I finally found a solution that worked for me. It seems that the drivers had become "screwed" and it was only seeing the headset as headphones and not as a full hands-free solution for the Bose (Plantronics continued to work fine).
I had to remove the Bose Headset from Bluetooth on the PC, then remove all drivers (including hidden ones) which related to the Bose. I then cleared all Bluetooth pairings on the Bose headset, and finally restarted Windows.
Following this, I repaired the Bose with the PC. This still did not work, and I then had to run the Bluetooth Troubleshooter. This got everything working for about 2 minutes. Then the Bose returned to headphone only mode. Checking Device Manager, the Bose Handsfree drivers were still not installed.
Removed Bose from Bluetooth on the PC only, then repaired the device. The device paired fine.
THEN LEAVE IT ALONE FOR 2 MINUTES as it installs the Handfree Drivers.
This finally solved the issue for me, and all seems to be working fine (famous last words). It really seems like it was a driver corruption/issue which needed a lot of resetting to get it working again.
I hope this helps someone, it was extremely irritating for me while the issue continued.
All the best and stay safe all,
Sanj