Measuring tall cylinders

Measuring tall cylinders


Does anyone know why it wont measure the last circle all the way around? I am using a 3x50 stylus that has plenty of clearance and should be able to measure the whole thing. I tried changing the angle to everything from 5-65 and cannot get it to measure all the way around. Also, I do not think it is a problem with the CAD model as this is happening on multiple models.