If something isn't working right with your program, there are a few things you can do to help get it back in working order.
Refresh the page 1-5 times
Logout and log back in
Restart
Check internet connection
Update Chrome
Update Zoom
Update your computer
Make sure you don't have too many things running in the background. Close out of unneeded programs.
If you are still having troubles, send in a support ticket with as much information as possible. Screen shots/videos are super helpful.