Noises like this are extremely rare, but can occasionally result from an enlarged joint or joints. (The Duo-Lyre® system uses specially designed dovetail joints to secure the microphone grip snugly, since adhesive can cause creaking sounds if applied to a moving section.)
By securing the mount with one hand and holding the Lyres steady, the microphone grip can be moved around to establish whether a loose joint is indeed the source of the noise.
We will happily have a listen to the unit here at Rycote HQ to confirm the fault, and will issue a replacement if necessary. If you are encountering this issue, please get in touch with a Rycote technical specialist in the first instance by submitting a support ticket.
Additional information on the InVision 7HG MKIII can be found in the following video: