parametric cell & Catalogue

Hello. 

I am using Open Buildings Designer- Update 5. 

I have made a Parametric cell using 2 local variables. A simple box. Width=Depth and a height. When I pull the parametric cell into the model it works fine and i can adjust the variables before it is placed. 

I then used the tutorial online https://www.youtube.com/watch?v=uLXodKLQcu8 which is more in depth than the Bentley page here. https://communities.bentley.com/products/building/building_analysis___design/w/building_analysis_and_design__wiki/40981/how-to-create-parametric-objects-using-cel-parametric

And I go through making a catalogue and in the definition editor i add "New Properties" for the variable height and width. And link it to the parametric cell so the parametric 

I use then use the "Object" tool to pull through the parametric cell. Before I place the parametric cell from the "Object" box i change the 2 variables. 

Then for some reason, the original variables used when i made the cell in the first place still remain. So i am getting some sort of merged cell. That is made up of the old variable dimensions and the new variable dimensions. 

How do I solve this?

Thanks 

Henry