dialog - ContentDialog disappears when showing StatusBar -

i've got strange behavior when showing contentdialog. when dialog on screen , drag statusbar down, dialog disappears.

private contentdialog _connectivitydialog = new contentdialog { isprimarybuttonenabled = false, issecondarybuttonenabled = false, title = "test"}; 

somewhere call _connectivitydialog.showasync();

i made simple project reprduce behavior: https://www.dropbox.com/sh/0a6ad5xtrzii7sx/aadnbf9tgpfjnv9xnvg4fqmja?dl=0

any idea why happens?

i found solution while investigating problem:

backbutton dismisses dialog.

solution:

_connectivitydialog.closing += (sender, args) =>             {                 args.cancel = true;             }; 

but aware hide()-method affected. can workaround on post: how prevent contentdialog closing when home key pressed in windows phone 8.1..?