How much excess paper is there around the cookie sheet? I find that if there’s a significant amount, it starts to smoke and burn. Always make sure the paper is just barely covering the cookie sheet.
How are the cookies doing? Is it possible your oven is not calibrated right, and you are baking at a much higher temperature that the paper is rated for? I had this problem with an oven once, set it for 350’, but it was heating to 500’! And make sure your paper isn’t touching the sides of the oven.
Parchment is usually good to 400 or 450 degrees F. If you’re going higher than that, it could be a problem. I’ve also had problems in the toaster oven, with paper that works fine in the regular oven. Of course, you could just have lousy quality parchment.
No, I just use the sheet once per batch - and it leaves a film on the cookie sheet too. Is that normal?
The temperature is 350, and the cookies turned out great. It is an old stove though, so I’m wondering if, even though the cookies turned out fine (and all things I’ve cooked in this oven over the last two years have turned out fine), maybe the oven is cycling up and down in temperature or something?
It shouldn’t leave any residue on the pan. Are you sure you aren’t using wax paper? It will burn and leave a residue. Otherwise it sounds like you got a bad batch of parchment, or a low quality brand.