Short touch delay using either Input or EventSystem classes

Hello,

I've created a very simple game prototype, with a build target of iOS, and I'm noticing what looks like a short delay before touches are initially recognized. Once a touch is recognized everything works fine (i.e. all touches work as expected). This is exhibited on an iPhone 6S.

The game prototype has two scenes:

1) Start scene that uses the EventSystem. When a player taps a UI Button, its OnClick event calls a function to start the game (i.e. load the Game scene).

2) Game scene that uses the Input class as part of the Update function (e.g. Input.touchCount, Input.GetTouch(0).phase). When the player taps the screen, a bool is set to true so a Jump function will work as part of the FixedUpdate function.

I've tried both of these approaches separately and noticed this same delay behavior. Am curious if this a known Unity issue or something else. It looks like there is a known issue with version 5.5.0f3 where the splash screen doesn't load. Wondering if fixing that would effectively solve this since it's only a few seconds delay.

Thanks for any advice. Appreciate the time!