Hi @robindelmundo,
It works now, thank you very much for the update!
Just figured it out myself.
I’ve had the exact same problem with registering users with Cyrillic names
So I had to rewrite code in plugins/wordpress-social-login/includes/services/wsl.authentication.php
The code line is 627:
if( empty( $user_login ) || ! validate_username( $user_login ) )
{
$exploded_email = explode( '@', $hybridauth_user_profile->email );
$user_login = sanitize_user( $exploded_email[0], true );
}