When i have 2 popups open and close 1 then the transparant background doesn’t show anymore, the div is still in the dom but the transparency doesn’t show because the backdrop-in class is removed.
I did a fix that works but i thinks there is a bug in F7:
f7.popup.close(el);
//Bugfix in F7, add class for transparent background back when we have multiple popups!
if($('.popup').length > 1) {
$('.popup-backdrop').addClass('backdrop-in');
}