I installed the plugin User Role Editor – https://www.ads-software.com/extend/plugins/user-role-editor/ – that is pretty simple to use. It lists the default WordPress roles and has checkboxes next to all of the actions available (with the default permissions check). You can add or remove permissions by simply clicking or unclicking actions and hitting “Update.”
Go to Author (or whichever role is having issue) and check the box “unfiltered_html” and update – and voila.
Thanks!