It's got some delay when I use "getRootNav().push(SomePage)" popup new page and click back button to close it

I used tabs to show some Parallel page, and used “getRootNav().push(SomePage)” method when need to popup a new page to above tabs page, It’s about a second delay in IOS when click back
button (left arrow) , can’t operate any element in parent page. Can anyone give me some advice?
thanks a lot~