Why does update remove values of my column

[#1]

All, 
    Wondering why this happens. I have an expression where a custom model is created. When I call this once, everything performs as expected, however when I call it more than once, one of the updates in the model generation fails. What surprises me is this does not happen when I update with one column but fails only with a specific column.  Any thoughts ? 

[#2]

when its done one column at a time, the data has a chance to completly update before the second one starts.

Try using the dt<<run formulas; trick to force the table to update before starting the next opperation. maybe?

[#3]

@Byron_JMP,

       This seemed to be bug in JMP 13.1 .I was unable to recreate it in JMP 14. However, in JMP 13, by reinitialise the namespace, i was able to fix ir