Security Admin Center Tenant Allow/Block List Not Able to Block IPv4?

While using the Security Admin Center Tenant Allow/Block List we have been able to block specific email addresses and IPv6 IP addresses but are unable to block IPv4 IP addresses. We have tried both using the console and the CLI but have turned up unsuccessful both times when it comes to IPv4. A large majority of the phishing attempts that we encounter come from IPv4 addresses but we have been unable to block any of these. Will there ever be functionality for IPv4 within the Tenant Allow/Block list or is the only option to use conditional access policies? Also why is this enterprise tool only functional with IPv6 and without documentation stating that it does not work for IPv4?