Question How do I add an object to my armature without breaking the bone rotation?

Im working on a model for a comic im making and realized that when an object of any sort is added to the armature in unity then it completely breaks how the bones rotate, it is like the added object works like inverse kinematics and instead of going upper arm>lower arm>wrist it goes wrist>lower arm>upper arm but it keeps going to the chest and hips too. I dont know if im describing this right because I have never seen this before and cant find anything on it too.
The rig works fine until something is added

When added the whole mesh breaks and acts like this

This is in unity 2019.4.31f1
I have tried a new version of unity and had the same issue
I have tried a new project and have had the same issue
It happens only when some object is added
It happens to any and all of my other models too

 

I haven't found a fix for it but believe it to be an issue with my unity install because when I moved my project from my computer to my laptop it worked without problem so I think I just need to uninstall and reinstall