How to activate SNI?
SNI allows a server having a unique IP address to provide the correct SSL certificate of the requested website even if that server hosts multiple websites and multiple SSL certificates.
To activate SNI for a specific domain, go to ‘ Multi CDN’ > ‘Origin protocol’.
On the ‘ Origin port’ box, click the ‘Settings’ (gear) icon located on the top right.
Check the ‘ Enable SNI’ checkbox, and click the ‘Save’ button.
An ‘SNI enabled: Yes’ status will be shown besides the HTTPS port to indicate that SNI functionality has been successfully enabled.
Check this article to learn more about SNI.