28-04-202301:21 PM - last edited 28-04-202301:30 PM
The only white tab I'm thinking of is edge panel. Is it edge panel you are thinking of? You'll find it in settings > display to turn it on, then when the edge panel bar is visible. Once pulled out you will see a setting cog to add what panels you would like. Then set up what apps you would like in split screen in the app panel. If it's not edge panel I have no idea what it is your looking for 😂.