Physics Contraint Locking Issue

So I’ve spent hours searching and trying to figure this out myself but I cant seem to find anything to help or how to fix this issue and its maddening.

Basically Ive got wheels attached to axles, locked all but the Swing 2 motion, yet EVERY single angular and linear motion isnt ‘locked’.

Im creating a physics based vehicle builder and as I add blocks to the machine the wheels move further and further upwards and the machine is lowered til eventually its sitting on the ground
(think a car when you over load the weight and the suspension sags under it and the body of the car lowers)

I DO NOT WANT THIS! I LOCKED the constraints to specifically prevent this! Ive toyed with projection values, ive toyed with turning on linear motors and limiting the travel and none of it is working!

All the values on the constraint are default except that I have locked all the linear values, this to my understanding means they shouldnt move at all, but they do, how do i get this infuriating quirk to go away?! Its literally breaking my entire game if a player cant add more than a few blocks before sagging the thing, the wheels should act like theyre directly connected to the block at ALL TIMES and not MOVE!

Any one got any Ideas?