We've just replaced the 2nd BTR and coated stock at 271 GSM prints just fine but when I try and run heavier 300+ coated cover I'm getting splotchy uneven areas of color. I've checked drum carts, calibrated the color density etc. At this point I'm thinking this may have to do with humidity but I'm not sure what types of visual flaws can be created by humidity? See attachment. Image on the left is a box printed last year, image on right is a print from today. Again, other jobs are printing just fine, it seems to have to do with the thickness of the paper. I've printed the same image on the heavier paper and thinner paper and get different results.