CLA states it's not required for existing contributors, requires me to sign anyway

1

PyTorch’s BSD license is not changing. There is no impact to PyTorch users. CLAs will only be required for new contributions to the project. For past contributions, no action is necessary. Everything else stays the same, whether it’s IP ownership, workflows, contributor roles or anything else that you’ve come to expect from PyTorch.

I’m an existing contributor, why am I required to sign?

2

Maybe you’ve changed or added an email address of your GitHub account, which triggers the CLA check again. Ask in the issue, if the PR is blocked.