Why are some websites in Safari not going through iCloud Private Relay?

Ever since upgrading to iOS 17 I have gotten this warning on certain websites: > **This Connection Is Not Private** > > iCloud Private Relay is unable to hide your IP address from this site. > By continuing to "[SITE NAME]" your IP address will be revealed. > >Show IP Address / Close Page When I go to the same site(s) on a Mac running Ventura, the site loads without any warning, and the option to "Reload and Show IP Address" in the View tab of Safari does not appear for those websites. In addition, one of those sites shows the IP Address I am using, and it's my "original" IP address - not an iCloud Private Relay one. Why do certain sites not load through iCloud Private Relay? Update: I found sites will load outside Private Relay without warning. Some sites will make the initial connection via Private Relay, but randomly go "outside" the service mid-browsing and lose the Private Relay privacy protections without warning. My concern is that sites can exploit this vulnerability by embedding a "non-Private-Relay" domain or site in their existing site, giving the site access to a user's IP address without warning.