Hi,
May I ask which plugin are you using for translations? Currently WPML and Polylang are fully supported only. Other plugins may not store the translation as a separate post type/user object, or might be within a custom field somewhere. I don’t think this is an issue with the database collation, that seems to be okay.
It looks like the actualy member name is stored as “SARI”, and the translation is fetched during when the user name is requested depending on the language. If the plugin you are using uses custom fields to store the translated data, it might be possible to search those, if the custom field names are known. Otherwise it may not be possible.