Hello there.
Recently a builder of mine just finished making a model for my game, and i started welding and rigging it like normal, however upon testing i noticed that the welded parts didn’t move the parent part, which was strange because they are unanchored. Upon further testing i found out that when i welded the parts it would just go stiff, but this only seemed to happen for the Head, and both Upper Leg Parts. I don’t know why it would only go stiff at the upper legs and the head despite when working with previous versions of the rig it worked fine. I tried resetting joints, starting from scratch numerous times, using rig/weld plugins, using weld scripts, manually welding them, and using motor6d but no solution to this was found. The custom parts seem to be making the parent part unmovable when the custom parts are welded to the parent, which is normally how i rig these sorts of models.
In the image below, the ones with the X on them are the parts that seem to be stiff and not work when welded.
Any help is appreciated.