incorrectly calculated article quantity

Hello,

in our onlineshop, we have many products which are packages of 11 single products. On orders where 2 bundles are ordered, they should be multiplied to 22 products.

In some cases, instead they are multiplied to 33. I weren’t able to reproduce this problem yet, but so far it only happened with 2 bundles and 33 products.

Here is a screenshot of an example order:
https://i.ibb.co/0sV8bP1/screenshot-product-bundles.png

And here is the product which is contained in the order:
https://zuckerschmuck.com/shop/dexcom-en-3/dexcom-tapes-g4-g5-en/sparpacks-dexcom-tapes-en/value-pack-101-flower-pink-2/?lang=en

Is this a bug and could it be fixed?