Have you increased the number of decimal points (Setup > Project Preferences > Editors > Decimals)?  Sometimes the TCE of the material is small so you can’t see the change with the default of 3 decimals.  Also, what’s your material?  If you’re using a glass, the TCE in the Material Catalog should be greater than 0 and if you're using a MIRROR, then the TCE in the LDE should be greater than 0.  Finally, to properly calculate the spacings/ring contact, OpticStudio also needs to calculate the change in clear semi-diameter (SDIA), so you should also include this operand.  It's recommended to use the Make Thermal tool (in the MCE toolbar) to properly populate the MCE with the correct operands. 

Thanks @MichaelH . Increasing the decimal points did the trick. Pickup calc matched with hand calculations. Both elements are fused silica. Noted on SDIA and tool recommendation.