My game works fine in TestFlight - complied and exported with the latest version of AGK. All images, sounds and music show and play as expected.
As a matter of interest - when you broadcast the game using the AppGameKit Player on your iOS device do the images display correctly? Using the AGKPlayer may be a good way to trace the issue.
Edit:
Just to add that I am having trouble with the AGKPlayer (and TestFlight version of my game) on a device running iOS 8.1.1 but that's a separate issue. The game runs fine in the AGKPlayer and via TestFlight on my devices running iOS 10.3.3. I have reported this issue.
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