That doesn’t make sense, it isn’t your phone that connects to a service, it is the speakers. Changing phones shouldn’t make a difference, the speakers are the same no matter which ‘remote control’ is connecting to them. 

I would recommend that you submit a system diagnostic from both phones, and call Sonos Support to discuss it, or post the diagnostic numbers here for a Community Moderator to pick up.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis.