Unity classifies any object with a Collider but as a "Static Collider." The engine assumes these won't move and caches them for performance. If you move a parent that has only child Static Colliders, the physics system might not update their positions in real-time.
If you move a parent using transform.position or transform.Translate , you are teleporting the object every frame. This can cause the physics engine to "lag" behind the visual transform, making colliders appear stuck or pass through objects. collider not moving with the object - Unity Discussions unity collider not moving with parent
Remove the Rigidbody from the child object. This makes the child collider part of the parent's "Compound Collider". Unity classifies any object with a Collider but
If both the parent and child have a Rigidbody, they act as . While they may look connected in the editor's Transform hierarchy, the physics engine treats them as two separate objects that do not automatically move together. This can cause the physics engine to "lag"