Amazon Music - Airplay stops, reverts to iPhone

Every time I navigate away from my Amazon Music app, or open another app, it disconnects the Airplay2 playback from my bluetooth streamer, pauses playback and reverts the Airplay2 playback to my iPhone.

This happened out of the blue, but reading another post I worked out that you need to switch off the built in Alexa which has worked. I would have replied to the post, but it didn’t allow any replies, which is poor as I could only vote that I had the same problem and not confirm that disabling Alexa resolved the problem for me.