HomePod status Stopped vs Paused vs Not Playing

I have three HomePod Mini's and three HomePod 1st and 2nd gen's, some in pairs and some stand-alone. Currently in the Home app they are showing three different statuses that all seem to mean the same thing: "Stopped", "Paused" and "Not Playing". What is the difference? I have been having intermittent synch and response issues and I'm wondering if this is normal or signs of a problem...

Thanks,

Chris