Sound issue on iOS

In my game, I have a video playing before the game itself begins (short instruction about the game).
After the video ends, I destroy it and the game starts, but the sounds in the game have delays and after a few seconds they are completely mute.
I have checked in the code, the app tries to play the video (sound.play() is ran) but there is no actual sound coming from the game, it’s like it somehow becomes completely muted.
This only happens on iOS. Works perfectly on PC’s and Android.
Does anyone have an idea about what might be causing this?