How to create a Horizontal Scroll in different aspect ratios?

Hello, I am trying to use a single image that can be scrolled Horizontally throughout multiple Aspect Ratios from 16:9 to 21:9. My Canvas is set to 5120x2160 (21:9) and Match Height @1. I have created the scroll view where it correctly scrolls Horizontally in 16:9 and reaches the end of the picture on both sides. At 21:9 it shouldn't be able to scroll at all. However, at 21:9 it scrolls past the image and shows grey bars. How do I fix this problem?