Peaches have a shitty pectin content so they don't jellify on their own. Next time I'd add powdered pectin, lemon juice, or a second fruit with high levels like plums.
Is it on parchment paper? It looks like it stuck to the bottom while it shrank, I imagine parchment paper would have pulled with the fruit leather so it doesn't crack, I'm not an expert though.
Get a square, fold it until you end up with a triangle where one corner is the centre of the square (basically fold in half 3+ times), can cut the inner and outer edges way easier to fit circular stuff that way, what I do when I line Dutch ovens. Seriously makes it actually manageable