Audio connecting, but no sound being heard by others in the meeting.

Hi All, 

I have a HP Athlon laptop with the latest version of Zoom. When I start a meeting the audio connects straight away but the sound bar doesn't move when I speak, others can't hear me and it doesn't record my sound. I've tried uninstalling and checking the audio settings but to no avail. 

It works fine on my tablet and the audio works as normal on my laptop while using Google Meet and Skype.

Any ideas on what could be wrong?