After updating Unity to 2018.3 and Vuforia to 8.0.10, Unity's Screen Space Canvas doesn't size properly on the AR Cameras. I've tested them on normal cameras and they size perfectly for them. What appears to be happening is that the height of the screen space canvas appears to be inverted from the actual height. Closer to camera is taller, further away is smaller.
I've tried creating a new canvas after the scene is running, I've tried switching a canvas between the AR Camera and normal cameras with the exact same camera component setup (it's correct for normal cameras), and I've tried resizing the canvas.
Somehow, it appears that any camera controlled by Vuforia Behaviour is breaking my screen space Canvases.
I've attached screen shots of various configurations below.