Yeah, I thought it sounded like the usual suplex problems. I have written reams about these particular items, none of it complimentary.
Search suplex on the forum.
Suffice it to say that the dampers are not fit for purpose, due to being copies of the original mgf damper which was designed to work with hydragas, not coil springs. Then bodged to make them sort of work...
The clonking is most likely the spring seat contacting the canister.
You can look forward to your rear damper top mounts cracking away from the panel...
David