In the most recent update to WordPress, a new WYSIWYG editor was introduced, called Gutenberg. This is intended to allow a lot more flexibility for users to customise the look and feel of their content without needing to edit HTML.
We encourage you to learn to use Gutenberg and let us know of any problems you come across by contacting the Service desk (email@example.com).
However, as this is such a big change and may not be the best fit in all situations, you may prefer to disable Gutenberg, and we have installed a plugin that allows you to do so.
To disable the new editor please contact the helpdesk (firstname.lastname@example.org) FAO PMITS Web team, and we will revert your site to use the classic editor.