With the Note 10 + Android 10 update. If I switch over to the Google gestures it doesn't allow me to go back. I'll keep Samsung gestures for now
Are you using any kind of third party launcher?
I had to turn off one handed plus. If you have that app turn it off
You can swipe from either left or right of screen to go back, if you have one handed on, you need to turn it off
Swipe from either the left or the right at the bottom of the screen.