Imported image size and quality issue

I'm seeing issue with image rendering.

I have project that is 960x540 and a PNG that is 1900x8500 pixels (very long) and when I import it, Storyline renders it 121x540. If I make it 100% Scale, that only brings it to 458 pixels wide and the quality is also degraded (the original image quality is crisp). If I make it full screen width (960), the quality is terrible. 

960 is just over 50% of the file's actual size but in SL it's ~220%. I can't share the actual file, but below is an example of an equivalent file with just some text.

Why does Storyline not see the real dimensions of the file and render it correctly?