Issue with humanoid skinned rig

  1. What do you want to achieve? Keep it simple and clear!

Create a custom rig for a game, not to upload on the marketplace.

  1. What is the issue? Include screenshots / videos if possible!

The lower and upper torso are influencing the rig incorrectly.
When rotating the upper torso the lower torso starts spinning rapidly and when rotating the lower torso the only thing that moves is the white grid underneath the feet.

  1. What solutions have you tried so far? Did you look for solutions on the Developer Hub?

Applying transforms and rescaling the mesh in both blender and studio.

Every other limb including finger bones are working correctly.
I created the rig based on the default armature provided by roblox and only modified it by moving the bones around to fit the mesh and adding extra bones for the fingers.