All sounds randomly stop on iOS after reward ad

I play music in my game while the user is playing. When the game is over, the user can revive their game if they watch a reward ad. When the game continues, the music plays again. This works 100% of the time in debug mode, as a web game and on Android phones. It does not work every time on iOS devices.

I have included my code but I am not sure that my code is an issue because it works on all export types except iOS.

This is where the music starts:

This is where the music ends:

This is where the reward is shown:

This is the reward ad callback:

This is where I resume the game:

Does iOS have special requirements that I don’t know about?