I have a map page that works just fine. From that page the user navigates to a new content page using PushModalAsync. On that new page I create a new map and a new MapView and add that to a grid which is my content.
The problem is in the space where the first map existed that intersects with where the new map is supposed to be I see the old map "on top" of the new map. I cannot interact with the old map but can interact with the new map.
Some things to note:
If I set the old map to IsVisible = false before the PushModalAsync it still shows on the new page. At that point if I go back (PopModalAsync) to the first map page the map will not be visible. If at that point I PushModalAsync again to my new map page I still see the same effect even though the previous map is not even visible anymore.
I've confirmed it's related to the first page by not adding it to the content of the first page in which case the 2nd page looks fine.
First map with map zoomed in!
Second map you can see the zoomed in map along with the new map (fully extent)