S8 D3 front suspension knocking

[Prefferle]

Hi folks, more challenges with my much loved S8. For several weeks I’ve been trying to sort out a persistent knock in my front suspension and it only occurs driving on uneven road surfaces and potholes like on country roads. I’m hoping that someone can point me in the right direction. So far I’ve replaced all front top and lower suspension arms and links with Meyle HD, Also replaced complete stabiliser bar with Audi OEM. I have checked the steering ends and checked for play on steering knuckles and rack and all feels tight and the car steers tight with no apparent play.
Still having this rattle! It’s mainly audible with no feel on the steering. My air struts work perfectly up and down smoothly. I was thinking that on a normal car suspension this noise can be a top strut mount or the strut itself but I’m not seeing this sort of strut failure on the forums. Do I need to replace the air struts? Any thoughts on what next would appreciated. Thanks