Player Can't Interact With UI

Hello all. I have been working on an options menu for my game and just after finalizing the volume settings section I could no longer interact with my UI. Both in play mode and the built application I have checked that I have an event system and that they are all children of a Canvas object and have Interactable switched on in all GameObjects. Does anyone know whats going on?

I made a new canvas and copied over the children of the old one and now it works.
I would still like to know what was causing it though.

In my case I just forgot to add a Graphic Raycaster component to the Canvas.

for me i had another image in front of my button that blocked all raycasts