Apps not showing 'proper full screen' in 'Navigation bar space' in Android 10

[AliRazaShafi]

AOA. i updated my s9+ to android 10 today. i have turned on the gestures (without hints, so the navigation bar doesn't show). first thing i noticed after the update was that all the apps (system and third party) all are not showing in proper full screen (meaning they are not showing content in the navigation bar area). hence the bottom of the screen stays unused and all the apps that show menus at the bottom don't look good. there is visible/noticeable space left.

 in android 9 there wasnt any space reserved for the navigation bar. apps were completely showing content on full screen. you can see the attactched screenshots. 

green line besides "recent tab" in Caller app. SEE HOW MUCH SPACE IS LEFT UNDER THE MENU in both version. and its like this in ALL THE APPS (system and third larty). really hate this design.

  anyone noticed this? 

anyone know how to revert to previous design without downgrading to android 9? 

Update: Fixed it. i had installed custom theme engine "Hex installer" that supported android pie i guess. uninstalling it fixed the issue. Thank you everyone for your help.

[MalikNomee8]

downgrade krna b nhi chahiye

[ZainIftikhar]

its your individual device issue.
my app shows full screen as shown in pic.
restart the phone and update all the system apps in Galaxy Store.

[AliRazaShafi]

All the apps are updated. even checked some system apps that are sometimes manually updated. restarted saveral times. still same issue.

[ZainIftikhar]

i guess its a bug then.
try changing the gestures in navigation bar and using navigation keys for some time. after that revert back to gestures and see if the problem is fixed or not.

[UzairQureshi]

touch that black side and then tell me what happens to the application?

[AliRazaShafi]

nothing happens. i checked in various apps. its usless. it shows almost everywhere. even in this members app. and even when i type its under the keyboard. (keyboard is slightly upwards than before.)

[UzairQureshi]

may yeh bol rha ho ap nay us gap wali sode pr click kiya hai tuo uskay baad kiya option araha hai??

[AliRazaShafi]

Update: Fixed it.
i had installed custom theme engine "Hex installer" that supported android pie i guess. uninstalling it fixed the issue.
Thank you everyone for your help.