Hi everybody, I am using RASPBERRYPI3-MODB-1GB sd card sandisk ultra 16gb a1 and i having a Audio interferance problem when i streaming to a speaker with bluetooth only when multi-room is active.
No problem with multi-room on and spotify or usb or webradio.
Seems that audio change speed costantly and sometimes jumping signal.
Thanks for your help 
Hey there @George91 and welcome to the forums. As a first step I’d recommend taking a look at the troubleshooting docs. Unfortunately using the on-board bluetooth on the Pi 3 doesn’t always give good results and the only real way to make it reliable is to use a dongle but if you check the docs there’s more information there too. 
Hey thanks @chrisys i forgot to tell you that i tried also with and without dongle (using raspberry bluetooth) but still the same. i will read the documentation.
Connected more raspberry via ethernet with a router i am not using wi-fi.
Many thanks