During that period when I was using my headset for calls, I would sometimes notice the audio kept cutting out. That sent me down a troubleshooting rabbit hole, which eventually led me to a relatively unknown Windows feature called Handsfree Telephony. It lets Windows treat your Bluetooth headset as a proper communication device rather than just a pair of wireless headphones. You still get uninterrupted audio through your Bluetooth headset while your laptop (or external mic) handles voice input instead. Instead, the culprit was a Windows feature I'd never really heard of before.