Music App on Mac stops playing when I play a movie in Photos App

Today I was playing music on my macbook, using the Music app, and then I went to my iPhone and went to the photos app and from one memory I played a movie and then my Music stopped playing on the mac saying "More than one decive is trying to play music" Asking to upgrade to family plan. I mean, what? First of all, I should be able to play music on my iPhone and Mac at the same time if I want, since they are both my devices, no one else. Second, it is a movie from the Photos app. What does it have to do with the music app?