Issues with iPhone 6S

We’re having a very odd problem iPhone 6s’s. The problem only occurs on about 10% of 6s’s and if you get completely out of the app (swipe it away) and then re-run the app it works fine.

The first time you start the app after rebooting the phone, pieces of the user interface are missing.
.link:correct interface

.link:incorrect interface

Any help is greatly appreciated.

Using Unity 5.6.2