Apple Music vs Roon on an iPhone with TWS headphones

Hi

A question, and hopefully a solution if one is possible

When pottering around the house I often have my TWS headphones in (Final ZE3000 - excellent BTW) and have noticed that perceived SQ is vastly superior from my iPhone 13 Pro if I’m using Roon to output to the phone as distinct from listening to exactly the same tracks via Apple Music

I acknowledge the limitations of bluetooth etc, but given that the hardware is identical, why might Roon sound so much “better”? All the tracks from Apple Music are “lossless” and stored on the phone itself, whilst with Roon I’m using the phone as an endpoint only

I’d be interested in a ‘fix’, if such a thing is possible, so I can enjoy the same or equivalent SQ when out and about

Cheers for any insights

Are the files between Apple Music and Roon in the same format and from the same masters, or is Roon streaming from another service such as Tidal or Qobuz? And is the volume set the same? Even a slight change in volume tends to trick the ear that the louder sound is “better”.