Mini Kossel Z Calibration Issue

I have been through calibration a few times now and I can't seem to dial in the Z Height on my prints. My calibration print is 20X20X5. The print is printing 20..1X20.1X5.5. I have my steps per mm @100 for all 3. It passes a paper test across the entire bed and if I measure Z movements of 10mm(across the entire bed) they are measuring perfect. I'm really at a loss as to what could be going on. Any input would be greatly appreciated.

Thanks!