It’s worth noting the “Repeat” flag is also in a different spot than it was when this video was made. It’s now found in the CanvasItem’s “Texture” section.
When “Repeat” is off, my maze looks like this:
When “Repeat” is on, my maze looks like this:
The texture seems normal in the inspector:
It looks to me like the texture is being repeated horizontally, but not vertically. I’ve looked around at other settings and also done some googling but I can’t seem to find anyone else talking about this problem.