Your public IP address is a IP Version 6, a sorta new thing that is replacing the previous IP Version 4. In a nutshell, the site software was never made to be compatible with IPV6, and while for most things it doesn't matter, there are some exceptions, and Rating Threads is one of them. That function requires an IP address to be attached to the report, and the site won't recognize your address.
This is a core software failure, meaning it's a hard one to fix. We have techs looking into it, but for the time being, there are ways to change your public IP address from V6 to V4.