Zoom meeting recording – has no sound!

I was recording an interview on Zoom and when I tested the recording beforehand there was no sound! It is an mp4 file, and I have done these a dozen times before and always had sound. It has no sound in Windows Media Player, or any other file program on my computer.

There is something I experienced recently that I think may relate to my current problem:
I was watching Star Wars recently in VLC Media player, and lost the sound. I have a kitten who sometimes steps on my keyboard, and he pressed something (I believe the top of my screen said 0% volume across the top right for a moment) directly before the Star Wars sound went out.

Does anyone have any advice on how to fix this?

Thank you!