Overlap seems likely. One thing I noticed that also applies to curing garments properly is the amount of layers underneath can affect cure time. Meaning if you have the bottom folder over, under part of the print, that part would have a slightly harder cure time even though most curing comes from the top. Sleeve underneath the print could be a factor too (but that would be less noticeable than garment overlap). Try a few tests with your settings. Fleece needs more time in the dryer!