Volumio not synced to other Airplay Devices

Hello at all,
I am new to this community.
I have several Raspberry’s with DAC and also a Beolit12 and a soundmate airplay device.
If i play music via itunes the beolit and soundmate are synchronous.
Also the raspberry devices with volumio on it are sync on their own, but they are about half 1s faster than the other two devices.

Now the question is can i add a value to volumios airplay software to get all those devices synced??
Do i have to play with buffer or how can i do this.

Hope any of you guys can help me with this topic.
Thank you very much.