We can deduce:
1. It is not the LX at fault (your 43 Ltd focuses fine), therefore the problem must be the lens.
However the lens works fine (on k1) when autofocussed.
Possibly a wobbly element that is held firm when the screwdrive is engaged ? Have you tried manual focus with the K1 ?
Give the lens a shake and let us know what you can hear ?
Edit...just seen your last post. So the 43 Ltd does not focus fine with the LX after all
Possibly the mirror is not sitting properly and this is throwing your focus off. Did you have a "sticky mirror" syndrome addressed with the CLA ?