Describe the bug
When adding a new post (/wp-admin/post-new.php), in the section entitled Document, in the Author scroll box, I have only the first approximately 70 authors out of 150 that write for the site. I am missing half my list to choose from.

Similarly, in the Categories section, I am missing many of the potential categories that are usually listed.

However, if I go to All Posts (/wp-admin/edit.php), and I click quick edit, my categories appear as does my full list of authors.

I would like to restore this functionality to the new post (/post-new.php).

Can anyone please tell me what is going on and how to fix it?

Thank you.

Note that i just moved from a very outdated Go Daddy self directed Linux hosting to Go Daddy Managed WordPress hosting. I was pretty old school and finally caved into getting my ssl and all that.

To reproduce
Steps to reproduce the behavior:

1. Go to /wp-admin/post-new.php
2. Click on Document, Click on Authors
3. Scroll down to find authors whose names come after Nadiya B
4. The names are not there

Expected behavior
I expect to see all the authors listed.

Screenshots

Additional context

• Please add the version of Gutenberg you are using in the description.
• To report a security issue, please visit the WordPress HackerOne program: https://hackerone.com/wordpress.

Oops that was the wrong screenshot...