Firefox+Firefox-Developer: The connection to localhost:39301 was interrupted

Hello,

while using Firefox and Firefox-Dev, preview does not function. I tested on 4 Browsers; Chrome, Brave, Firefox, and Firefox-Developer-Edition. The bug was only present on the latter two. I am running Arch Linux, running BSS version 4.5.1.

I use FF and I also use the included dev tools, i.e., responsive design mode; preview works for me.

The port I use is 8000 and not 39301.

PervasiveRichesLLC, in fact, I do too use port 8080 as well. I did some digging around and that port (39301) is used for the auto-reload. It's some port that the browser listens to for automatically reloading the website upon changes. That is what is giving me issues, and is not functioning.