A network error occurred while checking the subscription - Family

Hi. I have a Deezer family account. My son is on my account and has selected to download songs to listen to while offline (not on Wi-Fi and he doesn't have data on his phone). Whenever he trys to use the Deezer app offline, he gets "A network error occurred while checking the subscription. The application will close." Why is this happening? It sort of defeats the purpose of listening to his downloaded songs while offline if he can't use the Deezer app. Could you tell me why this is happening?

Thank you in advance.