Problem with flex grid system on iPhone 5s (iOS 9)

Created by: fsasvari

The grid system is not working on both Google Chrome and Safari on iPhone 5s with iOS 9 installed.

We are using Bootstrap v4 alpha-6 SASS version with including only files we need. Website works on all other devices - Desktop, laptops, tablets (iPad and Android) and other mobile phones (Android, Windows Phone).

• Operating system: iPhone 5s (iOS 9)
• Browser: both Safari and Chrome
• Website: https://www.poljinos.hr/en/

The problem is with grid system, it is displaying all col-* items in one row and website is more then 100% wide.

Any suggestions why this is happening ?