Epson SureColor P6000 - Extra Space when Printing on Rolls

[Haystack]

I recently started using an Epson SureColor P6000 and initially if I wanted to print, say, 24" x 30", it would cut the roll at 30". Lately it has started adding extra space—around 1 - 3 inches, which I have to measure and trim off manually. I'm printing using the Epson drivers. Does anyone have any idea what might be causing this, or how to work around it?