5.4 Modular Rig LEGS NOT WORKING

I’m trying to rig some models that I found on sketchfab in modular control rig and on both models I’m working on, the controls on the legs don’t seem to work despite them being connected to the right bone. The top half works okay (more or less), but I attached the bones the same way with legs and the controls don’t do anything. Can anyone please help with this issue as majority of tutorials I’ve found seem to be more focused on rigging already-perfect models as opposed to issues we may run into rigging custom models.

I am happy to go further into detail if you have questions. Any help I would greatly appreciate, and I understand this may be a novice question. I am rather new to vfx. Many thanks!