bluetooth distortion on iphone Xr

Just got a new iPhone Xr. After setting it up I put all my music onto the phone. I found that some songs suffered from massive distortion when played through my bluetooth speakers/Airpods. But when played over a connected set of ear buds the sound was fine. I phoned apple support and I played them the distortion. They advised me to change the iPhone XR for a new one, as I had only had it for 4 days!

Reloaded the new iPhone Xr and guess what??? It's the same!!!!

The same songs play fine over Bluetooth from other Mac`s/iPhones.

Anybody else had the same problem?

The song most able to distort the iPhone Xr is: Mozart: Requiem In D Minor, K 626 - 5. Sequentia: Rex Tremendae (Arleen Augér, Cecilia Bartoli, Etc.; Georg Solti: Vienna Philharmonic Orchestra & Chorus)