Music stops on Chromecast when I turn my Smartphone on

[groovebrother]

Plan

Premium

Country

Germany

Device

OnePlus 5

Operating System

Android 9

My Question or Issue

HI, the music stops on Chromecast when I turn my Smartphone on. I get the speech message (German) over chrome cast "Die Wiedergabe wurde gestoppt, weil Spotify auf einem anderen Konto genutzt wird" (somehting like: Playback has been stopped, because your spotify account is being used on another device).

But I started the play on my Android phone and use the phone as a remote controller.