Chosen Solution
This only happens while I am on certain apps. The slide up bar is there, but when I slide up it doesn’t do anything until I slide up like ten times. Is there a trick to slide up while you’re on certain apps? It works just fine on others.
The “slide up bar” will often go dormant while you’re using some apps in order to allow you to use the full screen - even the part usually taken up by that bar. To activate it again try tapping on it, you should see it get whiter and move up slightly. Hope this helps!