Dynamic Paint - brush not paiting canvas blender 2.81

I’ve got a question guys! So I’ve been following this tutoral (link qued up to the time where I get lost) https://youtu.be/11F1NRpqrzY?t=460 and I cannot seem to get the sphere to paint onto the canvas.

I’ve set the sphere to a brush and then added the bursh


Set the plane (with the ocean modifier) to a canvas, and then added it.

But I cannot see the dynamic paint affecting the canvas as it is in the video. No blue outline when I HIDE the sphere.

hmm. I thought, maybe it was because the plane that the ocean modifier was on was too small, but when I turn off the ocean modifier and scale up the plane, it doesn’t show the blue dynamic paint as I’m assuming it should.