Create and add custom classes to existing or cutom widgets

I want to extend or clone the container widget and add 3 dropdowns. I want it to be dropdowns or some other controls to make it more customer friendly than adding classes like you should do.

I managed to get the dropdowns in the correct spot and the classes to be added, but they only work when I save and refresh the page. The classes doesn’t change instant.

I managed to do this on a custom heading widget but it doesnt work the same on the container widget it looks like.

Would be really nice to get some guidance as I am quite new to bricks.