2 accounts influence each other

[problemsolver19]

Goodday, my english isn't very good so excuse me for that... Me and my brother have got a problem. We've got a family premium account, and use both our own account. But, when he listens with a Sonos system, I can't play music on my Macbook. It says, 'your account is paused because it is used somewhere else'. But we use different accounts, so I don't understand. When he doesn't use Sonos there is not a problem. 

I've got my own house at least 15 kilometers away from my brother' house. And I still get the same notifications..

Do you have a solution? Please let me know!