After viewing an admob ad on iOS, the sound disappears in a game created on Unity

Hello everyone. Trying to create a game on Unity!

Such a problem: After viewing the ads (test or real) provided by Google (I connected admobe), the sound completely disappears. This happens ONLY on iOS, on Android there is no problem. It does not save the subsequent reloading of the scene or switching to another scene. I tried to restore the parameters AudioListner and AudioSourse, i.e. they are not exactly muddy and make a sound. I have analytics enabled and, no error seems to come. I have already tried all the banal options, the sound on the iPhone is definitely turned on, Mute Other Audio Sources is disabled. Buda is grateful for any help and is ready to supplement the question with the necessary information.

Don't know if ProjectSettings or my code is needed?!