In the Web Protection reporting is a display issue listing, where the URL/Domain isn't a hostname but a IP address.
Examples:
Domains and URL's are listed correct as
googleadservices.com or sophos.com
from IP addresses only shows the last two figures as "domain" or "URL"
138.114 or 62.180
Please make sure, that there somehow will be checked, if the URL / Domainname is a IP address, and display it accordingly. (I don't use IPv6 - but I assume it may handle those addresses also wrong)