Knowledge Checks disabling custom buttons on iPads

I have found an unusual issue, might be a bug. I'm wondering if anyone else has seen this issue before?

• This only shows up when viewing the lesson on the iPad.
• I am publishing to HTML5
• It is a non-responsive project, a fixed size.
• I am using Captivate 2017 on a Mac

The Captivate file:

• There are some content slides with text, audio and images, then I have a Knowledge check slide, then more slides with text, images and audio.
• I have made my own movie controls, the default playbar is turned off
• The pause/play button is one button that has 2 states, pause and play. There is a variable and advanced actions to pause/play the movie and to switch from one state to the other.
• The movie pauses at the end of each slide, there is a next button to move to the next slide and a previous button to go back.

What is happening:

Everything works great until the user hits the Knowledge Check page. The pause/play button is hidden on this slide. Then when the user moves away from the KC slide the play/pause button appears. But the button no longer functions. As I tap it, it no longer switches states or pauses/plays the movie. If I tap it enough, sometimes it will pause the movie, but does not always switch states. It will not play the movie again, if it had paused it.

Again, this works fine on the desktop, its only on iPads that this issue happens.

Thanks!