Correct as of the current release. I wouldn’t say that it sits there talking to itself (although I admit that I /have/ tried “Hey Mycroft, say hey Mycroft”) but it’s got progressively worse to the extent that the only way to get it to recognise anything is to talk loud while it’s still speaking it’s acknowledgement. See
Can you expand on the context-specific tones approach?
It would need coding, but basically just a brief “Bip” or similar as a marker.