Cannot download Flutter package

What version of Codex is running?

web

Which model were you using?

default

What platform is your computer?

MacOS

What steps can reproduce the bug?

Go to chatgpt.com/codex, on my repo ask it to do this:

Help to run the tests and fix errors. Don't use `--offline` when downloading dependencies

And this is the summary:

I attempted to run the Flutter tests for the IdeaSwipe mobile project as requested. Running flutter pub get or flutter test requires downloading dependencies from pub.dev. Due to network restrictions, the commands could not reach pub.dev and failed to complete. Consequently, tests could not run.

When hovering on the log icon:

Proxy failed to establish tunnel (403 Forbidden), uri=//pub.dev:443

Note this this is consistent. I have tried this many times and still get same behavior.
My environment already has full Internet access.

What is the expected behavior?

Packages in pubspec.yaml can be installed and flutter test command can execute to completion, without complaining about network errors.

What do you see instead?

Test cannot run because packages cannot be downloaded

Additional information

_No response_