We use a .dev domain as a localhost alias, and turns out his ISP’s DNS wouldn’t resolve 127.0.0.1 (or whatever it is) for the .dev domain. Changing his resolver at the network level to 1.1.1.1 fixed it.
I imagine there are lots of difficult support tickets for app devs, and at a certain point they just hardcode the DNS to remove one variable from the equation when debugging bug reports.
Only problem was that nobody in my family out of state could see it. It took awhile to realize realize that we never bought that domain. Our local ISP just added it to their DNS records, and since we all hooked into them we thought we were live across the 'net.
I remember one of the first times I used the Internet and opened my local radio station’s website from several states away. It was incredible to me that it worked and I also wondered why anyone across the country would care. The early internet was amazing.
I agree that it’s usually the right behavior.
Related story, there was a period of time where my ISP's resolver that would replace hostnames with no DNS record with their own ad filled garbage page.
So you mistype google.com to foofle.com or something and instead of getting "host not found" you get... ads.
Disgusting behaviour IMO.
