Keeping a tab alive in the sidebar

Hello all,

I have added YouTube and YT Music in the sidebar.

YouTube keeps playing when I minimize the sidebar, YT Music does not.

My goal is to keep YT Music playing when I minimize the sidebar.

Is there anybody who has an idea how to make this happen?

And what is the underlying mechanism that keeps one website active, and the other not?

I have YT Premium so closing background play is not the issue.