Why are Raycasts not working in the UI?

Question

Unity

There is a Canvas overlay on which a transparent Image is stretched with raycast target enabled (Needed to control the player through IDragHandler events, etc.). There is also a world space canvas that has a button. This button does not respond to clicks. How to fix it ? I think that this trouble solves the settings changes in the GraphicsRaycaster, but it doesn't work for me. BlockingMask changes are completely ignored. If you remove the raycast target from the canvas overlay on the image and put "UI World" in the Blocking Mask, then put layer "UI World" on the world canvas, raycasts will work, although this is not logical. Or am I misunderstanding something?

Overlay canvas


settings World canvas


settings Camera settings