Audio works on test speaker and microphone but participants can't hear me nor can I hear them

I'm having the same problem, mic test works but people cannot hear me. MacBookPro. Can anybody actually help with this? 

I had a similar issue a while back. The built-in Zoom tests showed that my microphone and speakers were working, but I still couldn't hear other participants, and they couldn't hear me.

What helped was using a third-party tool like Sound Tester's microphone test to verify that the microphone was actually being detected outside of Zoom. Once I confirmed the mic was working properly, I realized the issue was related to Zoom's audio connection settings rather than the hardware itself.

If anyone is troubleshooting a similar problem, it's worth checking with Sound Tester's microphone test before spending too much time changing device settings.