Out of interest, are you guys using Starlink or something like it?
Sometimes I cannot connect to npm when I am using Starlink (which I think issues shared IP addresses), but when I connect to an actual VPN it lets me run npm installs etc.
I get similar behaviour with some Azure connectivity as well.
This might not have anything to do with the actual issue, but just thought I would ask in case it is related.
Possibly related behaviour also mentioned here: