Node 2i Disconnecting w/ Apple Airplay

Hello,

I have my Node 2i working just lovely with my iPhone when I stream from the phone with Airplay.  The problem I encounter is if I stop playing music, about 15 minutes later, the connection drops, so if I hit "play" again, it plays on the phone only and I have to re-connect to the Node 2i again.  This is obviously very annoying: is there a way to fix this? Thank you!