MD pushed page z-index issue

I’m using Beta9 now. Not sure when it starts. if it’s IOS theme, pushed page will be on top of parent page without any problem. However if it’s MD(android), pushed page is “floating” on top of parent page. Parent page can be seen at the edge of DIV blocks. Looks like opacity setting with backdrop?

I have to add higher z-index to all pushed page.

z-index: 11;