Powder Coated PEI Sheet Flaking  

Powder Coated PEI Sheet Flaking

I have a powder coated PEI sheet that I've been using for about 4 months and about 3-4 kg of filament in that time. It has become my favorite spring steel sheet option because of the nice finish I get. I use it with PLA and PETG. Recently the sheet has begun flaking when I take the prints off. I typically just let the printer naturally cool down and by the time I get to the print, it has basically popped itself off the sheet. Sometimes, I have put it in the freezer to get a rapid removal. Lately the prints have been stuck even after cool down and I noticed bits of the coating are missing from the sheet and are embedded in my prints. Thus my print and one side of the sheet are now ruined. I haven't tried printing on the other side since I noticed this problem.

Has anyone else experienced this?
Is there a care and feeding guide for these powder coated sheets that I missed?

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Mark