Clash sphere Point transromation from P.B.P to model orign ( survey point )

I wrote a script to generate clash spheres from NavisWorks report into revit model. Here I attached the part which takes the points data that read from XML report ( converted to Excel ) and do transformation from project base point to model origin.
The problem is that the Z coordinate which transfer to node:
“FamilyInstance.ByPoint” interpreted wrong and the instances were created not in right Z coordinate. I have to say that sometimes the data is read well and I get the right clash spheres location.
Here is an example:

Is anybody can help me understand what is wrong with this code?
Thanks for your help.

With the same files and data, I run it again , but inserted watch node between Transformation code block and “FamilyInstance.ByPoint” node
and got right spheres locations. it works right sometimes and sometimes