Since file -b says the downloaded file is an html file, it is probably an error page from cloudflare ... rename the .zip file to .html then view with browser to see what CF might be telling you.
Also ... might want to check your certs using SSLabs checker.
https://www.ssllabs.com/ssltest/
One should not be running any ssl protocols these days .... tls 1.2 or higher.
Also ciphers could be reduced ... SSLabs checker will tell ya.
IF you PM me the FQDN and real IP address of your server I can do some remote testing for ya and get back via PM.
'SoS', Ken