Hi @js-enthoven_2797,
Unfortunately I'm not very familiar with debugging apt :(
The only one I was familiar with was the InRelease-related error, which you worked around.
Otherwise, I haven't seen these before, but they seem to be warnings, so maybe it's okay and is working? It does say "All packages are up to date".
I don't really know what they mean, or if it's related to ProGet, apt configuration, or the package I searched for the text of these errors ("No Hash entry in Release file"), and there are a lot of suggestions on what to do... they are all different, and I have no idea what might work.
The "Connection timed out" is really strange too. Maybe it's related to proxy, or something? A blank page is to be expected if you have no packages in that scope; otherwise you will see a number of "Paragraphs", one for each package.
Cheers,
Alana