Fails to clone private repo when running from Actions (in same repo)

I used the Azure Kubernetes Service (AKS) Deployment Center to create my deployment pipeline from Github. Everything worked until earlier today when this message started appearing:

/usr/bin/git remote add origin https://github.com/myaccount/myprivaterepo
/usr/bin/git config --local gc.auto 0
/usr/bin/git config --local --name-only --get-regexp http\.https\:\/\/github\.com\/\.extraheader
/usr/bin/git config --local http.https://github.com/.extraheader AUTHORIZATION: basic ***
/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 origin +a68375c71a1bc2e93d149534598be84261d0c9ca:refs/remotes/origin/prod
remote: Repository not found.
Error: fatal: repository 'https://github.com/myaccount/myprivaterepo/' not found

The script generated by Azure has - uses actions/checkout@master, which I thought may be deprecated. I tried a few versions to no avail.

[MisterTimn]

We are running into this error as well now… Private repository. Both checkout v2 and v3 erroring…

[TamaMcGlinn]

I’m getting exactly this error today, but for private submodules, using:

      - uses: actions/checkout@v2
        with:
            submodules: recursive