FASTPANEL - не выпускается SSL lets Encrypt - Certificate can not be issued as URL - is not available for verification

Ошибка при выпуске SSL Lets Encrypt сертификата:

Certificate 'site.com' can not be issued as URL 'http://site.com/.well-known/acme-challenge/0zUL04vUyy76tgyEXrRz' is not available for  verification.
Received response is ' <!DOCTYPE html> <html> <head> <meta http-equiv="Content-type" content="text/html; charset=utf-8">
meta http-equiv="Cache-control" content="no-cache"> <meta http-equiv="Pragma" content="no-cache">
meta http-equiv="Expires" content="0"> <meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>404 Not Found</title> <style type="text/css"> body { font-family: Arial, Helvetica, sans-serif; font-size:
14px; line-height: 1.428571429; background-color: #ffffff; color: #2F3230; padding: 0; margin: 0; } section, footer
{ display: block; padding: 0; margin: 0; } .container { margin-left: auto; margin-right: auto; padding: 0 10px; } .response-info
color: #CCCCCC; } .status-code { font-size: 500%; } ', expected response was '0zUL04vUyy76tgyEXrRz'

Причина - домен с самого сервера пинговался на другой IP.

После исправления /etc/resolv.conf через resolvconf на 8.8.8.8 и 8.8.4.4 - сертификат был выпущен без ошибки.