Steps to reproduce:
1) Open the attached project.
2) Build the project for iOS.
3) Deploy the project to a device via Xcode.
4) Open the app.
6) Press the GUI 'Button'.

- A custom input module is used in the project. GetTouchPointerEventData().CurrentRaycast.gameObject.name should be logged in Xcode console, however if 'Screen Space - Camera' is selected as Render Mode on the Canvas element, no message is logged. The message is logged if 'Screen Space - Overlay' is selected (expected behaviour). This issue was not present until 5.4.0b22.

Note: this issue can also be reproduced using Unity Remote.

Reproduced on:
5.5.0a1, 5.4.0b23, 5.4.0b22

Did not reproduce:
5.4.0b21, 5.3.5p5