I have computers and Motu Ultralites in each side of the Cat6 cable. If I put only one switch in one of the sides (switch to connect the AVB interface + a computer), and connect the interface without switch in the other side, it works well. So Cables and switches are ok.
But having a switch in each side connected by the same cable (and a computer and an audio interface in each switch) doesn't work. The led doesn't even flash.