Receiver with wrong account matched

[Garfield62]

Hello, i have a big problem. I have a Denon X6200W. Last year my son was on visit.

He has a spotify premium account. logged in my wlan and matched my receiver with his account.

Now he can remote play music from another country on my receiver. We can not stop this.

now i have a premium too, but i can not found my receiver with the spotify app, so i can not play my music on my receiver, but he can do.

How can we solve this problem?

I think the "ID" of my receiver is matched on the spotify server with his account.