Creating a github clone from a PX4 version

PX4 Autopilot
1

Howdy. I want to perform work on a specific rev of PX4. i thought I would:

  1. Fork the PX4-Autopilot repo into a private repo
  2. Within my private repo (which is the fork), perform:
    % git fetch --tags
    % git checkout -b my-branch-name v1.14.0
    % git push origin my-branch-name

But the above fails with an error of “error: failed to push some refs to ‘github.com:MyRepo/MyForkName.git’”

Any hints on how to set up my private repo without an error?

Thanks!