UI scaling too big after build

I have been trying to figure this out for hours. My 2D game works fine in Unity. After I build it (on mac), the buttons on the main page are scaled way too big, with one of them off the page. I am able to click play, and the next scene works okay, but the score (also UI) is too big and not in the right position. The canvas is already scaled with screen size and matched to fit screen. Any ideas?!?!