go post this same q? in power lifting-and you will get some more specific advice.
Ill give you a big ass hint
weak glutes not knees is what causes knees to cave- ( usually)
allot of it can start with ankle mobility- or over supination (rolled out feet)
and travel up the leg to the hips that way.
add more glute specific warmups- glutebridges - one leg glute bridges
Weighted Glute bridges- with a barbell will do wonders for your other Pchain stuff.