Keynote problem in exiting Full Screen Mode in Zoom

My keynote got locked up when I tried to share the screen in zoom - using Sequoia 15.7.3

Why is this happening? I tried the commands : command control F to get into full screen and then to get out of full screen and that did not work. I also tried option-command -esc to force quit keynote but that did not work.

I ended up having to shut down my MacBook Pro - 16" 2023 laptop

Can anyone explain why this is happening?

Thank you

Susan Z