The 443 is included in the Local Service Firewall Rules. Somewhere in this forum is a complete list of whats in the local service rules, but you can think of it as anything hosted by the OS itself. IE, 4500 for SpeedFusion Data, 32015 for handshake, 443 for SSL Web Admin.
https://forum.peplink.com/t/firewalls-ports-speedfusion-local-service-firewall-etc