As a mentioned. (please read all the recent comments), i will change to elementor according to your steps again but for the meantime, we would need to have the WP bakery site working until we changed.

Also, please the list of complaints i made well. The example you shared does not reflect the solution to the problem. Pleas read very well our list.
On that particular problem, we mentioned that the first or single product adding to the cart works well but it is when you are adding a SECOND item to the cart that you experience this problem.