HomePod mini has a problem connecting to the iPhone

Hi, my HomePod mini has a problem connecting to the iPhone.  Siri says my iPhone isn't available.  I can control the music by simply tapping the HomePod icon in the control center.  When I press and hold, it shows that the HomePod is not playing and the timers are unavailable because the HomePod is not on the same network as my iPhone (but it is).  How can I solve my problem? 

I have tried several times to reset (delete and re-pair) my HomePod.  I also restarted my iPhone, but the problem still occurs.