After updating my galaxy A7 2018 & A50 to android 10 both devices are having same issue of full screen gestures not working properly as compared to previous android 9's full screen gestures...specially i have to swipe up more than one time to go back
Settings>Display>Navigation Bar> select Full Screen Gestures> Click 'More Options' in the full screen gestures section> Select the second option 'Swipe from Side and Bottom.
Please try above steps, if it's not working please let us know.
I've already tried that but i wasn't comfortable using those gestures...may be it will take time to get use to swipe from side gestures... But i like swipe up gestures so I'm gonna use them...may be some update sort this issue out
