More problems trying to add packages from private repos

Another diagnostic would be to use

julia ---startup-file=no and rerun versioninfo(). That will completely rule out any contribution of startup.jl.

Also check your shell startup files such as .profile, .bashrc.

Edit:

In this case the issue ended up being due to a rogue VSCode-Julia extension setting. To resolve, clear the “Package Server” setting for the Julia extension within VSCode.

See here for more details:

Having an incorrect JULIA_PKG_SERVER will make it challenging to get new packages.