Product variants generation problem

I have a product that is already configured and variants generated. Now I add one more value to one attribute. I should now get one new product in addition to the already existing variants generated earlier. However, if I click « Generate product variants », Axelor generates all product variants, and I end up with many duplicates. QUESTION: what is the way to use the existing model and, upon expansion of the attribute values, generate just the new, i.e. additional, product variants without duplicating the earlier generated existing ones?

Hello,
When you generate variants the column is_model, parent product (COMP-0002), goes from FALSE to TRUE

With the action-view which displays the list, the products with the is_model column set to TRUE are no longer presented. Therefore, difficulties arise in regenerating new variants from the parent model.
One solution is to remove self.isModel = _isModel AND from the action-view product.root.product as follows: