It looks like I may have found a bug related to PushPage on the Android client. I created a page with three device browsers on it (one in each of three columns). Then I added a button to call the PushPage method of App to show the page.
The first time, it works as expected. However - if I then go to another page and press the button to do the PushPage again, the page comes up, but I only see the button backgrounds. None of the other controls show.
This is 100% repeatable for me, and doesn’t happen with the Windows client. As a further test, I decided to try opening the same page I’m using with PushPage, but instead I just set the Page property of another page browser to that page. I can go back and forth to it as many times as I like and it works as expected. So it appears to be somehow related to using PushPage, and only on Android.
I’ll add that to fix it, I have to close the app and restart it.