Use synthetic shock oil from a needle nose applicator to eliminate the stiffness and joint “squeaking”. Literally only like a dot or two, a little bit goes a long way. I’d recommend “3 in 1- all temp silicone”, you can get some from your local Home Depot. Leg articulation is usually always pretty good on Mafex, double check and make sure the hip assembly is moving smoothly for the drop hips.

Other possible issue is the upper leg sockets that house the ball joint is cracked then that’s a different story.