Microphone works but no one can hear me

[mg101]

My built in microphone on my laptop works fine in every app and even when testing my mic on zoom. I have done test calls and the person can hear me and my mic works fine. But After being in my meeting for 2 hours and I unmute to talk in the meeting. the host or my classmates cannot hear me. The mic is unmuted and the mic icon does not show that it hears or detects me. Everything is up up date and no other apps are open. I have uninstalled and reinstalled zoom and still problem is there. Just started having this issue, never had an issue with zoom before a month ago. Please help as it gets frustrating not being able to participate in class.