not sure if this started with firefox 74 or not. But whenever I make phone calls in Gmail, I no longer get the permission popup asking for access to my microphone. The padlock in the address bar shows no attempt for permissions to the microphone. My microphone permissions under Options doesn't list any sites to allow or block. I even tried doing a firefox refresh. Still, gmail does not prompt at all for microphone permissions, but other sites, (like voice.google.com) work fine. Also, I get no microphone in the call itself - so it isn't just that it isn't prompting because it remembered a setting. The gmail site doesn't reflect any microphone access at all when making a call and doesn't work.