Custom template not working as expected

Problem/Motivation

When I try to add custom classes to the form-actions divs, the template creates a new set of divs

Steps to reproduce

Add custom classes to {{ view_cart_button }} var like this:

Then there is a new set of .form-actions divs that have the a tag hidden (display:none). And the original buttons are still there, too.

I'm puzzled by this behavior. Usually when I add a twig template to my custom theme, clear the caches, I can then override it by adding my own classes, etc.