I was frustrated at my Sony XM4 headphones cutting out and playing a sidetone instead every time you start talking during a meeting. Since I was using it on my Mac I couldn’t turn off the Speak to Chat functionality through the app settings. Here’s the fix I found!
To turn off this annoying feature, hold two fingers down flat on your right earbud until you hear a “Speak to Chat deactivated” message. You might need to try a few different finger placements (just holding for a few seconds should do)
Credit to hiiamhere1 for this solution (Wh-1000XM4 CUTS OUT WHEN TALKING? : sony (reddit.com))!