Thank you for your post.
I believe this is because the 'Header/Door Height' and 'Door Height' fields are the same measurement. If you change the 'Door Height' field (you'll need to tick the 'Highlite?' field to enable it) to be less than the 'Header/Door Height' value it should fix the problem. Please note that the 'Door Height' field is only used when adding a highlite so that the door panel(s) height can be entered/set.
Would you be able to please let me know if this fixes the issue you're having? If it doesn't, can you please send the model to firstname.lastname@example.org
so I can look into it further.