The search function stopped working for one user’s name after the display name was updated to first last (using the Force First Last plugin). The user display name was formerly the email address and was turning up in the search function. I changed the display name back to the email address this user is still is not found in FEP. I have tried logging out and in. I have deleted the Cache for all pages. I have restarted my server. I have tried different browsers. Same result.

I am seeing the current posts for this user to the user and the name is displayed first last. But when I try to write a new message to the user I receive “No Matches Found”. The name is not found in the FEP directory either. This is only happening for this one name. All other names work. I have looked at the wp-user in phpMyAdmin and the formatting appears as all other names in the WordPress database. I do not see any odd carriage returns etc.. I am seeing the user pop up in other applications within WordPress using the search function within the other applications. So, this is some issue with how FEP is grabbing the names. I have not had this problem before in FEP or when I have used the Force First Last plugin. I have been using both for many years.
The only one updated recently has been FEP. Any ideas on where I can look next?