This is the second time I've actually run into this issue. The aggregate step does not like the use of a GetParent function in a formula. The first instance was on a job where I was subtotaling an amount at the GL Entry Header level. Then I built an aggregate step at the detail level that added a detail line where the gl amount was the total from the header plus another value at the detail level. No matter how many fields I set to decimal - it kept treating the two numbers like strings, so instead of adding 2 +3 = 5, it would give me 23.

Today, I was working on an order posting job, and I wanted to pull the Order Header location into a conditional formula at the line item level in the aggregate step. We insert a catalog item onto the order and want it to ship from the same location as the rest of the order. Again, I used the GetParent function to pull the value of the order header location, and it ignored it. So, I had to go to a prior map step and build a formula at the line item level with GetParent to grab the value and then had my conditional formula in the aggregate step just look at that formula.

All that to say, there is something "hinky" when you combine the GetParent function with the aggregate step. thanks!