Padding, Margins and Other Styles Are Not Applying On Elements
If you're trying to drag top and bottom margin or padding handles and the element's margin/paddings are not changing, there might be other styles which are forcibly overriding any style changes. This can also happen when you cannot change backgrounds, borders or when transparent images always get a background color.
To find the problem, open up your browser's inspector and inspect the element. Browse the styles for that element. If you see something like this:
Then you can be sure that either your theme or a plugin is preventing any other styles from being applied to the element. Mouse over the stylesheet to find out which theme/plugin it's coming from.
To fix this, remove the "! important" part of the style, and you should be able to apply styles again. You may need to contact the author of the theme or plugin to fix this.