I’ve seen slow downloads of the ISO before. Maybe it’s intentionally by sourceforge but if you accept their ‘privacy policy’ the download speed seems significantly faster…
IMO an unacceptable way of forcing you to accept unwanted cookies.
And yes, we did see this before: https://community.nethserver.org/t/download-nethserver-iso-from-sourceforge/14535
(I see that link points to a discussion in the ambassadors section… you might not be able to see it)