Thanks for the info. I do wash all my plates with soap and water regularly. I’m not having any adhesion issues with them so far. The marks on this particular plate do not wash off and they don’t seem to affect the performance of the plate - they just leave matching marks on the objects printed on the plate. And though, as I said, I’m not having any adhesion issues, I do assume that the marks are caused by the adhesion being ‘different’ on top of those spots and the actual spots themselves obviously aren’t physically transferring to the object.
I am aware of the sheets to replace old ones as they wear out, but this entire plate is only 2 weeks old and has been used maybe 20 times at the absolute most. Surely it shouldn’t need to be replaced that quickly.