Before_widget won’t show up

Thanks to Tom J Nowell I found out that the reason for after_widget and before_widget NOT appearing was that I used my own widget and inside my own widget I had commented out:

        //echo $args['before_widget']; 

and

        //echo $args['after_widget']; 

So as soon as I tested it with the default wordpress “Custom HTML” everything worked fine and before_widget and after_widget appeard as expected.