Cannot access new git branches

🐛 bug report

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project
  adheres to.
• I have searched the issue tracker for an issue that matches the one I want
  to file, without success.

Description of the problem

Any new branches created on a public repository cannot be accessed by codesandbox. The issue has been observed on two different repository, and on multiple newly created branches despite similar code and file structure

How has this issue affected you? What are you trying to accomplish?

Cannot create new version branch to demo within codesandbox.

To Reproduce

New Failing Branches:
https://codesandbox.io/s/github/coveo/atomic-documentation-codesandbox/tree/2.29.0/
https://codesandbox.io/s/github/coveo/atomic-documentation-codesandbox/tree/2.30.1/
https://codesandbox.io/s/github/coveo/atomic-documentation-codesandbox/tree/test/
https://codesandbox.io/embed/github/coveo/headless-documentation-material-ui-react-codesandbox/tree/version-2.17.1/

Existing (Working) branches:
https://codesandbox.io/s/github/coveo/atomic-documentation-codesandbox/tree/latest/
https://codesandbox.io/s/github/coveo/atomic-documentation-codesandbox/tree/2.28.0/
https://codesandbox.io/embed/github/coveo/headless-documentation-material-ui-react-codesandbox/tree/version-2.16.5

Your Environment

Start by comparing the failing and working Codesandbox branch URLs listed in the issue, then trace how public GitHub branches are fetched and opened. Done means newly created public branches load in Codesandbox consistently with the existing working branches; the issue names no source files or tests to run.