In response to 0.0.0.0 day, Firefox Nightly version 131 had introduced a new security measure: blocking access to 0.0.0.0/::/::ffff:0.0.0.0 addresses. This change is currently live for Nightly users and will be gradually rolled out to all release users in the near future. Before we implement this ch...
And of course adding an exception or turning it off doesn’t work either.
Perhaps a bug then? AFAIK, “developer edition” is basically just nightly.