pfSense

There is no need to `urlencode` user credentials (CURLOPT_USERPWD already encode them):

curl_setopt($ch, CURLOPT_USERPWD, urlencode($this->_dnsUser) . ':' . $this->_dnsPass);

/services_dyndns_edit.php: Dynamic DNS noip-free (XXXXX.ddns.net): _update() starting.
/services_dyndns_edit.php: Response Header: HTTP/2 401
/services_dyndns_edit.php: Response Header: server: nginx
/services_dyndns_edit.php: Response Header: content-type: text/plain; charset=UTF-8
/services_dyndns_edit.php: Response Header: cache-control: no-cache
/services_dyndns_edit.php: Response Header: www-authenticate: Basic realm="No-IP DNS Update API" 
/services_dyndns_edit.php: Response Header: date: Thu, 10 Jun 2021 09:49:39 GMT
/services_dyndns_edit.php: Response Header: content-length: 9
/services_dyndns_edit.php: Response Header: 
/services_dyndns_edit.php: Response Header: 
/services_dyndns_edit.php: Response Data: badauth\x0d

OK, without `urlencode`:

/services_dyndns_edit.php: Response Header: HTTP/2 200
/services_dyndns_edit.php: Response Header: server: nginx
/services_dyndns_edit.php: Response Header: content-type: text/plain; charset=UTF-8
/services_dyndns_edit.php: Response Header: cache-control: no-cache
/services_dyndns_edit.php: Response Header: date: Thu, 10 Jun 2021 09:45:06 GMT
/services_dyndns_edit.php: Response Header: content-length: 18
/services_dyndns_edit.php: Response Header: 
/services_dyndns_edit.php: Response Header: 
/services_dyndns_edit.php: Response Data: good X.X.X.X\x0d

Regression of #11815 (pfSense Plus 21.05)

https://forum.netgate.com/topic/164263/any-known-issues-since-update-dyn-dns