I’ve had a MK4S for over a week now, and 100% of the prints I’ve tried to make on the textured sheets have partially or totally failed. PLA prints beautifully on the smooth sheet, but PLA, PETG and ABS, I think I could print on the surface of a 10 inch tank of oil with more success than the textured sheet. Plastic doesn’t stick to it. I’ve wiped it with isopopyl, I’ve washed it with dawn…it’s a bad print surface and I want my money back.
I use a textured sheet for all of my Prusament PLA prints on my Core One and XL, and it’s never given me a hint of trouble. I’m using the Prusa-provided profiles with zero tweaks.
I just hit it with a bunch of 99% IPA while it’s cold and scrub it with paper towels before every single print. I don’t heat it up until all of the IPA has dissolved, since apparently PEI is incompatible with hot IPA. I’ve never washed my sheets with soap, I’ve never applied any sort of bonding agents to them, and I’ve never sanded them.
Maybe you just have a bad print sheet?