"Alfonsogonzalez, Ernesto (GE Digital)"
> I'm still not sure what it means for the branch upstream to be 'origin'
If only you checked who the upstream of your 'master' was before
doing the set-upstream-to, it would have been trivial to answer that
question, but that is water under the bridge now.
A wild guess is that the upstream of your 'master' was 'origin/HEAD'
(whose name, when fully spelled out, is "refs/remotes/origin/HEAD"),
which pointed to something other than "refs/remotes/origin/master"?