Need help with fixing rig hierarchy

Hello everyone! So I’m new to Unity and I’m trying to post my MODULAR pack on marketplace but it it’s decline due to this issue as they say: Your character rigs hierarchy is not right. The model should have one root (not multiple) and all of the other bones should be inside it. So when moving a parent bone it would consequently move its child bones. Your models are made of different parts and every part has pivots and other same bones too.

I’ve asked for clarification but they keep sending about the same message. And they say - follow this example as on the left of the image attached. But my modular pack (on the right on the image) looks the same or am I missing something?