External microphone stops working in between Meet and Zoom calls (MBP 2010 on Sierra)

Hi everyone,

I've been facing an odd, intermittent issue with my mic. I am using a MacBook Pro (13-inch, mid 2010) with Sierra 10.12.6. (Temporarily until I get my newer MacBook Air's battery replaced due to swelling)

The internal mic stopped working on the MBP sometime back. So I started using a mic with a wired headphone, connected via a 3.5mm jack. The mic works fine when I check in the 'System Preferences -> Sound -> Input' menu when I first start the laptop. It also works fine when I try to record a 2 minute audio clip on QuickTime. The mic continues to work on Google Meet or Zoom meetings.

However, not more than 60-90 seconds into the meetings, the mic stops working (folks cannot hear me). When I look at the sound bar in 'System Preferences -> Sound -> Input', there is no movement, indicating no input. This has happened enough times now for me to notice the frustrating pattern.

The same thing is happening with a new Bluetooth headset I purchased, after assuming the problem was with the headphone microphone.

I've tried resetting the PRAM, this hasn't helped. Any suggestions for troubleshooting this odd behaviour would be helpful.

Thank you.