Hello,
This is fixed in cPanel version 70 with the following case:
Fixed case CPANEL-17902: EA3: Ensure the 'default SSL' vhost is bound to all of the shared IPs.
Fixed case CPANEL-17902: WHM: Do not display the 'default SSL' on the Manage SSL Hosts interface.
You can safely ignore that listing until your server is updated to cPanel version 70 (it's currently only available in the Edge build tier).
Thank you.