WP User Manager provides options to remove the nickname field from the profile, account, and registration form. It’s a field WordPress has out of the box, but not many sites need it.
To proceed in removing the nickname field, edit the Nickname custom field (Users > Custom Fields > Primary Fields > Nickname (edit).
From the ‘Privacy’ tab set it to hidden. Then in the ‘Permissions’ tab, you can set profile editing to hidden as well. Like so:
Make sure to save the settings to utilize the changes you made from here.
We also have a separate guide to stop the nickname from appearing in the display name dropdown on the account, you can access it from this link– https://wpusermanager.com/article/204-remove-the-user-nickname-from-the-display-name-dropdown-in-the-account-page/