I don’t think this is a bug, overlay screen doesn’t show the navbar because it’s an overlay, it’s in the name. Usually, overlay screens are for forms or info about the clicked item.
I continued using it as the other options don’t work with my app. The other option scroll all the way to the top upon click back no idea why very strange idea. So I decided to go with the flow and stick with my current set up. Not much can be done really