Custom module not getting extra classes

Hello, I have a custom module displayed in a section, but the HTML output from purity is not adding the extra class set for the module

I'd expected to get an extra "row" class in the HTML, like:

How are extra classes managed, or how should I add them to customize module output?

Under this Advanced tab, please try to change the Module Style to another style and see how it goes.

Regards

thanks that worked