Funky designs on FEP

[Dave64]

.125mm on the thickness. I thought maybe it was a static charge left over creating the designs, but that seems to go away after the PTFE treatment. Before that, on a clean/ dry FEP, my microfiber just drags across it with a scratchy sound and there is so much static that the microfiber sticks to it, even when flipped upside down. The FEP could just be a bad batch, my last set worked flawlessly for months and never acted like this.
Sound wise, all my FEP's hit 300-320 hz on the meter and they all do the same thing.