I fitted all new arms etc on front of my L322 about 12-18 months ago.
I have had a knock in the front for a few months now.
Seems to be both sides.
I'm sure all the arms were Delphi. I have seen many people complain that the Delphi only last about 12 months.
I have had a look as best I can to feel what's loose/worn but struggling to find anything.

(ARB links also changed more recently too)

We’re the arms tightened up with load on them? If there’s no weight on them when tightened then they fail early. 2011 (MY12) 4.4 TDV8 Vogue
2016 Golf GTI PP

Gone
Audi A4
VW Passat
VW Corrado G60
VW Golf GTI
BMW E30
Mini
Vauxhall Chvette

Yeh I think the bush(s) are ok. I recall reading in a few different places that the ball joints tend to fail pretty quickly. Wanting to see what the general consensus was on here.

I was going to suggest ARB bushes, have you done them as well as the drop links? I have a knock too but if I give the ARB a good shove it will recreate it so am going to change the ARB bushes and see if that solves it.