Motu 828Mk3 ADAT White Noise?

[EW1]

Hello Motunation!
I want to connect my Motu 828 MK2 as a slave via ADAT to my new Motu 828 MK3.
When I do, I hear white noise cycle through the channels 1-8.
This is on the Adat B channel since i already have an 8PRE on Adat A. I can also see this "bursts" of Whitenoise in the cuemix wandering from channel 1-8.
The ADAT A channel is working fine.
Does this have anything to do with the Worldclock? How do you get rid of it?
Thanks in advance
Erik

[EW1]

Thank you for your help, I figured it out finally. I had to have four ADAT cables and I had to put both of my devices to ADAT sync. Simple as that and now it works great!
Take care!