Question how do I prevent items added to a character from breaking posing

I'm working on a comic in unity 2019.4.31f1 and have run into the issue where an item attached to a character will act like a root like the hips and when posed instead of moving Upper arm > lower arm > wrist when posing the simple addition of any object will change it to go wrist > lower arm > upper arm. but it doesn't stop there, it will even move bones like the chest and keep going through the armature. I know it isn't the model that is broken because it was working earlier today.
- it moves fine when nothing is added

- now that I have added a cube it breaks, this can be done with any object

Something to note is that it just came in randomly, I was working just fine earlier and haven't imported anything in the past hour of work

Any help will be very appreciated, I'm new to working on unity in this fashion and it sucks having to get stuck on something like this