This is one of the first things I felt I had to change when this site was installed.
I don´t know if you, as wordpress user, are used to the new editor like the block default editor, or the gutenberg one. But I think if something works, then don´t change; that´s why I installed the Classic Editor Plugin.
Works like a charm. Now, I am ready to post!
In case you want to know more about WP Plugins and how to intsall them, check this link