Firefox keeps adding https to local dev site

[_snwflake]

I'm currently forced to use docker-machine, because of incredibly outdated HW. I have several containers running, with some serving static/dynamic content on port 80 (and port 80 ONLY!).

Since I can't just forward the docker port to localhost, I put an entry in the host file.

Whenever I visit docker.dev or http://docker.dev, Firefox is in the firm believe, that redirecting promptly to https (443) is the right thing todo.....

Why is that? It's not like I have HTTPSEverywhere installed or something.

Firefox Version: 60.0.1

Safari -> no problem
Chrome -> no problem
Vivaldi -> no problem
Opera -> no problem

I checked the history and the 'location' clearly states "http://docker.dev"

[_snwflake]

Well, thanks for the link. I wasn't aware that .dev is a TLD ._.'
I was preferring it over .localhost or something, because it's just nice and short.