Missing borders in Ionic 2

Hi, my iOS Ionic 2 projects have no borders on the items when I try to view them with the Ionic View App or if I try to browse them trough the Safari Browser on my iPhone (with Ionic Serve on my laptop they are perfectly working).
Here’s a pic of the Ionic Starter Tabs (untouched, I just ran ionic upload)

I have an iPhone 4s with iOS 7.1 and Ionic View App v. 1.0.6. Is this a problem with an older version of iOS, Ionic View App or what ?

Ionic info:
Cordova CLI: 6.4.0
Ionic CLI Version: 2.2.1
Ionic App Lib Version: 2.2.0
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 10
Node Version: v7.2.1
Xcode version: Not installed

Edit:
I think the problem is the 0.55px property on the borders. I tried to make this sample header with the same css property of ionic2 headers and I can’t see the border on my iPhone browser/Ionic View App.
Example on jsbin: