Why would you use an API endpoint to download files in a build pipeline? Surely you should just use a clone of the repository?
I could believe that an endpoint to download files looks at a cache, and if you are just using 'master' or 'latest' as opposed to a commit, I could believe that would be out of date.
Bit late, but replying to this because my comment does have missing context. Most of the repos we have are large enough that downloading three individual files is faster than cloning the whole repo. Even with a shallow clone with a depth of 1. I've tried the combinations and even tried downloading a zip file of the repo. Still faster to download the three files. And I haven't even added parallel downloads because it's fine as is.
But given the issues, why continue to use the API? Because those files are related to the build pipeline logic and they change maybe once in 3-4 months. I can live with an error once in 3-4 months. Recently I was working on changing some of the logic of the pipeline and that's when I ran into it enough to say that there was something odd from Github's end.
I could believe that an endpoint to download files looks at a cache, and if you are just using 'master' or 'latest' as opposed to a commit, I could believe that would be out of date.