Firefox’s default in-built download manager is hot garbage. It is so much more reliable to download multiple large files at once with a resource-friendly download manager.

Wow that’s strange. It always allowed me to continue as a guest without signing up most of the time before. I wonder what triggers it.

Are you using a VPN or private DNS? It worked after I disabled by VPN connection. It worked once on chrome too(with VPN), just once though.

Librewolf

Could it be because of my VPN?

Edit: Works in a different browser, Sorry for wasting your time.