I have some cherry that has been sitting in my shop for 5 years. Just for the heck of it I measured it at 12%. I wrote on it 5 years ago that it was measured at 15%. This didn't seem right to me so I looked in the manual for settings. I found a recalibration procedure. I ran the procedure and remeasured the cherry at the expected 8 to 9 percent. Maybe you just have to calibrate your meter.