Testing on older devices is something many (any it appears iOS) doesn't do well enough.

I ran into this with an apps verification system. Because of the positioning on an iPhone 7 you couldn't perform verification. When I contacted them I learned they don't test on iPhone 7's because they are too old. This was prior to the 11 coming out.

I've also had to help someone with this problem on their older device.

A casualty of always chasing new is design and QA for older devices.