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1 year agoI had a similar thing happen to my smooth PEI sheet. Forgot to change sheet profile before printing and printer made some noises during printing. At first thought that the sheet is damaged, but after several days noticed that the sheet is actually fine. The noise was the extruder skipping because there wasn’t enough room for the material to go anywhere, and the lines on the sheet were just a very thin transparent layer of the material. Difficult to say from the images, but the lines seem to have the texturing intact? That implies the sheet is fine. The thin lines are difficult to remove without damaging the surface, especially because you have textured sheet, so you can’t use any solvent like acetone.
If you can still separate the pieces: Take some big enough flat surface (has to be very flat) and cover it with sandpaper. Sand the pieces until they are completely flat. They will then connect without any gap in between.