When clicking on one line then the other to identify the dimension within, if the mouse is dragged outside of the boundaries, the dimension is doubled. How do I stop this from happening?
In the example, the .05 is the issue and the in-between dimension is the actual (driven) result.
This is by design and is quite helpful when you're designing revolves so that you can easily dimension diameters.
I'm pretty sure you can't turn it off. Just don't drag your dimensions across centerlines/construction lines during creation. You can drag them to the other side of a regular line without doubling. Once the dimension is created, you can drag it around and it won't change.