Hi and thanks for your quick reply Dylan. My setup is core connected via ethernet to Internet and the airplay speaker, Audiopro C5, connected via wifi (2.4gHz).
Answers to your points:
1: I just have one airplay enable speaker,the C5.
2: I realized about the problem three days ago cos I played a mixed format playlist. I use to listen to abums, not playlists, so don´t know how old is the problem.
Anyway, after the last Roon release with Chromecast support -Thanks a lot for it, really well done!!!- I´ll beggining using my chromecast audio instead of the airplay support of the C5 speaker: better sound and more versatile- so now I´m not worried any more about the airplay problem with my system related to mixed audio formats in playlists.
A note: I tested mixed audio formats playlists with chromecast audio and everything works as it should: no stops, for example, when going from an MQA song to a Redbook song or viceversa.
Anyway, thanks a lot and, really, congratulations to all the team that makes Roon such a great audio software, ecosystem.