How do I switch back off the desktop version?

scroll all the way down and u will see written really small mobile version

When u open a manga page you'll see a tiny icon that says "new version" on the top bar of the screen. Click on it

If u still don't understand, this might help
https://www.mangago.zone/read-manga/mangago_how_to_guide/

Thank you so much!! It was really bugging me

nppp, I hated it when it happened to me as well