Thank you very much for your answer, I think you are right but its a bit furstrating.
Lets say that i am coming home from work. I say hey siri play some dance music .Homepod responds and we are on.
Song starts to play and as you say i see the song that plays on my lock screen.
If i unlock and go into music app and choose another song from iphone it will stop what homepod plays and play the new song that i choose.( also at the bottom of music app i see the song that's playing from homepod mini)
After that i swipe down control panel and i press the airplay button on the music , i see the screen that has at bottom the option "control other speakers and televisions". Pressing that gives me the options of iphone and my homepod.
1) If i choose the iphone, it appears in control panel , lock screen and inside music app the iphones last song(homepod still plays the different song that i have chosen from before) . I choose another song from music app then my phone plays different song than homepod.
2) If i choose the homepod it appears in control panel, lock screen and inside music app the homepods music. I choose another song from music app then homepod starts another song and iphone remains silent.
I think that what you say it is correct because i close completly internet while i had the option 1 and homepod still carry on.
The whole thing needs refurbish in my opinion.