Unity adds normal and tangent to additional shader channels when enabling canvas

I’m working on a game with the 3D Game Kit template and in the menu, when I disable and re-enable a sub-canvas, ‘tangent’ and ‘normal’ get added to the ‘canvas’ component. This ends up making the canvas disappear.

Before disabling and re-enabling:


I’m guessing you’re using Text Mesh Pro somewhere on your canvas? It relies on these additional shader channels, so I believe it adds them back automatically.