So I guess the issue is the binding plug if not the receiver, what I read is to create a binding plug you connect the two outer wires on a servo plug and then plug it in to the bind slot, is that correct? If so I've done that fine. Then I connected the other servo wire which was pulling 5V via the sabertooth to the receiver, this gave me a red and amber light, but no flashing.

The AR6000x was never used before this so it'd be a shame for it to already be broken.