AirPlay issue

[Outkast27]

My mbpr is developing a habit in which it will not let me select my airport express for airplay in the sound settings. I click airport and it immediately goes back to internal speakers. Sometimes it does it and sometimes it does not. Im sitting 10 feet or less from my airport. How do I resolve this?

Thank you.

 

[Outkast27]

bump

 

[richard371]

I notice this sometimes on my late 13 rMBP. A reboot solves the issue. I see my denon and apple tv there and select it but it defaults back to internal.