I still don’t get why it’s only this row. There are lots of other sites that contain the same boxes (without the labelwrap and pricetag), for instace here
and they all work perfectly fine.
I will change the css like you suggested, I totally understand why it’s better. I just don’t get what is happening there.
regarding your other questions: The website is also responsive but not fluid since we like to keep 2 independent versions for mobile and desktop. Flexbox unfortunately is not an option at the moment.
Thanks for your help