Problem restricting access to public management interface for SonicWALL TZ 300

I need to access a TZ 300 externally from a fixed public IP. When I enable HTTPS management on the WAN interface, there is a rule automatically created as follows:

From: WAN   To: WAN   Source: Any  Destination: All X1 Management IP  Service: HTTPS Management   Action: Allow

I've created a rule strictly for my public IP, but I can't seem to get rid of (or even modify) the permit statement for Any on the Internet. Can someone point me in the right direction? Thank you.