UI - How can I prevent a Rect Transform on a canvas from blocking clicks?

Hello

Say I have 3 objects on a canvas, disposed as follows: (each is parent of the next)

      Canvas
        - object1
          - object2
            - object3

Now imagine each of these to be in ascending order in area, (area of object1 > area of object2 > area of object3).

Currently, when I check in event system and I'm clearly over the smaller object2 or object3 rect transforms, it flags it as being in object1.

I've also tried not making them parent -> child, and just one after the other in the hierarchy, but it did not help.

Strangely, I have a slider as a child of object3, which works fine and is interactive as it should be (in both hierarchal layouts).

How can I remedy this problem, and have object2 and object3 properly intercept the clicks?

Worth noting: object2 and object3 have an EventTrigger component; also, there is an EventSystem in place.