The problem with your property node is that you don't have the Active Cursor property. Before you read the x position, write to Active Cursor to select the cursor and then read the x position. In your case with two cursors, the sequence would be to select Active Cursor 0, read x, select Active Cursor 1, read x. You also should put some data flow between the while loop and the property node. Putting the property node on the right side of the diagram doesn't mean that it will execute after the while loop finishes. In fact, it won't.
