last SONY I attempted music streaming with was an STR-1060. The problem I ran into was to stream into the second zone you needed to use the music cast ap or google cast from your phone to the receiver. Upon doing this it would also change the primary zone to music or google cast. Then if you changed the primary zone back to DVD Or whatever it was on, then the streaming in zone 2 would turn off.
Does this issue still exist?
Would love to sell more Sony receivers but the zone 2 streaming is an important feature at least in my neck of the woods and just about every other brand does it from an app and does it reasonable well.