HomePod speak integration

Hello,

I can not find the right settings for the following scenario:
1) Radio is playing (initiated via Siri => play radio station xxx)
2) Indigodomo is via the Apple TV Plugin announcing a message
3) => how to arrange that automatic the radiostation continue to play.

Till step 3 its perfect working, but to get the HomePod start playing the radio again on the same station is the part which I don't get to work.

Looking forward to suggestions, thx in advance