The PHPMailer "SMTP connect() failed" error in WHMCS is almost always on the server side. Since you switched to a dedicated server and Cloudflare, check these quickly:
Your provider or firewall doesn't block outbound SMTP (587 or 465).
Cloudflare is not acting as a proxy for anything related to email (SMTP must be DNS-only).
GoDaddy SMTP settings are smtpout.secureserver.net, TLS, port 587, and auth on.
The From Email address in WHMCS is the same as the GoDaddy mailbox.
turn on WHMCS mail debugging and see if it even gets to AUTH
It's not the credentials that are blocked 9 out of 10 times; it's outbound SMTP.
