In the new update (1.15.2), it now goes back to full screen after switching from another app (immersion mode after suspension), so thankyou for that! But after the build category selection menu (which looks like a normal Android pop-up menu) is closed, the bar stays visible until I switch away and back again.
Turns out, if I select the building type menu (like research building, resources, etc) it causes the home button to show up, and not go away