Canvas Group with Blocks Raycast Doesn't effect onMouseUp?

I've got a panel with a canvas group that has "blocks raycasts" selected but doesn't stop an onMouseUp event on a sprite's collider behind it. Is there another step I need to take to get raycasts to be blocked by this canvas element or am I entirely misunderstanding how these two things should work together?

Edit: This issue remains switching onMouseUp to other onMouse events.

 

https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnMouseUp.html

OnMouseUp triggers even if the mouse isn't over the object, which means the block raycast shouldn't stop it. At least that is how I'm understanding the document. I haven't used OnMouseUp in awhile, so I might be rusty on it.

 

Thanks! I just tested it with a variety of other onMouse events but nothing changed. onMouse events seem to involve raycasts if I am understanding the docs correctly, right?

 

I've been able to find a work around but I am still curious as to why this doesn't work. Could anyone could shed some light on how these are supposed to work?