hello, this redirect is happening on the server-side, so it's an issue with your wordpress installation - please ask your question through the support channels that wordpress is providing to get a better answer.

In Wordpress, if the "root" of your site is under /blog make sure you have that path in the necessary places in the dashboard. Also, it might take a few reloads before Firefox recognizes the redirection changes. You can use Ctrl+Shift+r to bypass cached files when reloading.