Some mirrors don't open USB images as downloads
When I open https://tails.stalkr.net/tails/stable/tails-amd64-4.28/tails-amd64-4.28.img in Chrome 99, the image starts loading in the page itself, instead of being opened as a download. This does not happen on https://tails-mirror.applied-privacy.net/tails/stable/tails-amd64-4.28/tails-amd64-4.28.img for example.
Firefox behaves in the same way on both links.