Hi!
I tried to reproduce the problem with the example ReinforcementExamples/BarShapes/GeneralShapeBuilder. I set the function, that should create the shape to stirrup and tried to change the concrete covers to 35mm, 36 and 37. The cover you have marked on the image is the left cover. The bottom cover would be the second one. Anyway, I tried both and get the desired results. The problem may happen in combination with other parameters. There are too many of them for me to investigate one by one. Can you try to reproduce your problem with this example by providing the same combination of parameters? If you succeed, then tell here what the combination was. Maybe you will need to modify the code of the example - in this case post what you have changed.
I would like to help you, but I must reproduce the problem on my PC.
Best,
Bart