HTTP response to HTTPS client

Hi, I am having troubles in understanding how encrypted connection works on an influxdb instance installed on a server. I followed all the instructions. I modified the .conf file setting “https-enabled = true” and specified the paths for the certificate and the private key files, after copying them in the /etc/ssl directory. I set also the permissions on them, as documentation says. Restarted the influxdb service, but I get the error "server gave HTTP response to HTTPS client.
What am I doing wrong? Thank you for your help!