Another test to check if the function managing sending of that mail is reached:
Add this at the very bottom of your theme functions.php:
Notes:
1.- Take care not to leave blank lines after this.
2.- If your theme functions.php doesn't end with ?> skip first line of my code.
<?php
function cust_test_recover($text, $user, $password) {
error_log($text . '***' . $password . PHP_EOL , 0);
error_log(json_encode($user), 0);
return $text;
}
osc_add_filter('email_user_forgot_password_description', 'cust_test_recover');
?>
Check the output in debug log, you should see the body text of the email, the link to recover password and all the User data.
Regards