Problem Animating Sliders

Hi there, first time posting so let me know if this is not the right tag. I’m a problem when I animate the size of a slider the the first image in the slider scales correctly, but then when I fli through the slides they no longer fill the full slide area and instead seem to load in at the original size. How would I go about making sure that the slides fill the whole frame while still allowing the slider to grow?

Here is my public share link:link