On ipad inside mdDialog multiple touch closes both popups

[pianetarosso]

Hi, we have an ipad with IOS 11, the picker is showed from a form inside an $mdDialog.
The picker has date and time selection
When touching rapidly the "ok" button of the picker, both dialogs are closed.
Do you know which could be the issue?

Thank you

[hexadecy]

Which browser, Safari 11? also complete dependencies versions please.