Seeing your post I was actually worried because next week I wanted to install Bazzite on my laptop. For me the download worked fine though, 3-4 MB/s, its the bazzite Asus nvidia image. So it seems more of a problem with your internet connection somehow, more specific to wherever they store downloads.
Are you downloading with a download manager that could retry connecting when it fails?
Yes. Admittedly I don’t have time to test if it really boots. I wanted to do that some time end of next week when I got a day off to take care of stuff.