Turn on message tracing and then run an in-out exchange through SY for inbound (service binding) and outbound (reference binding). Take a look at the context properties and make sure everything we need is included and at the correct scope. If there's stuff that shouldn't be in there, remove it.

Some notes from what I've seen:
1) service name is at message scope instead of exchange
2) make sure other headers like service name don't bleed through in scenarios where a SY service invokes another service through a reference in a Camel route