I seem to be getting a black screen on bootup.

This is running on a Canakit PI3B+

Looks like a CMA error.

What size screen was this public image tested on?  The screen I connected was a 1920x1080 resolution.

Does it need to be smaller than that?

Can you set the CMA higher before install time? If so what is the proper values for a 1920x1080 screen?