SSL Cert. Issues

When trying to curl my https website I get an error,
Other websites works fine.

Code:

curl https://website.com
curl: (35) gnutls_handshake() failed: An unexpected TLS packet was received.

I've recently installed a fresh copy of ISPCONFIG on a new server and just copied the SSL fields from the old server's ISPCONFIG to the new one and clicked the "Save Certificate" button.
The website seems to work fine on regular browser, but I smell something is not ok over there. (And this curl issue is approving my feelings).

What did I do wrong?
How can it be fixed?
Why can't I curl my https server?

 

if you use ISPConfig 3.1 you could use Let's Encrypt to manage your SSL certs.

 

Thank you @sjau ,
But what difference does it makes for me right now, as my SSL certificate is already set up?
Just want to know if there is a way to know that everything is o.k. And what could cause curl not to work.

 

I tried your curl line on OSX and debian and saw no error

 

Thank you, I just found out that the problem appears to happen only when trying to curl my own server (from within the server itself).
Figuring the problem equals 50% of the answer.