background resolution not matching project resolution

I created a responsive project in Captivate 9 with a resolution of 1024 x 627. I then created a background with the same resolution. Upon importing the background to the master slide, it no longer fits. Specifically, the background appears too short (notice white space at the bottom). The same project with the same resolution in Captivate 8 does not have this issue. What's up with Captivate 9?

Thanks,

Darin