Hi
I cannot find any reason to Element.MoveByVector does not work.
The elements are legends components
Dynamo 2.0.3
Revit 2019
I am going to use Element CopyByVector from Clockwork package by I feel curious why this basic tool does not work.
I do not know if it is in the right forum category
What is the purpose of the Transaction.Start & Transaction.End nodes ?
Andrew
I thought that could help to sort out the issue. Before the vectors and the elements were feed directly to the node.
I am going to check if the problem happens when you repeat too many times the same script to adjust things.
You need to use Transaction.Start before the node Element.MoveByVector and Transaction.End after it 
