hello,
That's a side effect of the fact that you define the quantity input for "default", instead of "inherit", that leads to display a different quantity input specific for this specific product.
All have a
div to build the quantity input, and for "
Joomla-1-1-40-m" it's a
table, and so that's leads to some side effect, with different css command.
I allow myself to correct this settings, and you can see that this leads to a more homogeneous result.
Hope this will help you to better understand the situation.
Regards