I have about 1,500 user accounts (subscribers). When I go to the Users section of the WP admin/backend area, and then try to search for a user, it is very unreliable. If I search for a last name or first name that I know is there, it often doesn't return that user. Or, it will return a few users with that same last name, but not all of them.
Is there some sort of limit on the number of users that WP can search? The search does seem to be reliable when I search by email address, but not by name. For example:
I have a user named Sharon Williams. I searched for "Williams", and she appeared. I searched for "Sharon" and she did not. I searched for "Sharon Williams" and she did not.
Additionally, I have a user name John Williams. He did not show up in the search for "Williams", "John" OR "John Williams".
They both show up if I search by their exact email address.
Any ideas what's going wrong? I'm not getting any errors or timeouts that I can see.