Canvas will not fit to screen upon build

I did not change anything that should have made this happen but suddenly the build is compressed. It was full screen upon build a few days ago.

It looks good from the editor.

I am not sure how to fix it, I feel like I have tried everything on here. I tried removing the image from the background, playing with the aspect ratios and resolution, changing the fullscreen modes in player settings, changing the render and UI scale mode of the canvas… I must be overlooking something simple.

Anyone have any idea what happened or how I fix this?

In canvas scaler component of your main canvas. Set the UI scale mode to “Scale with screen size” and then set your desired screen resolution in the “reference resolution” property.