Help: Trying to setup triangular workflow

["Matthew B. Gray" <hey@xxxxxxxxxx>]

 Hello

I am trying to set up a triangular workflow against a fork. The example I'm
using is documented here: https://git-scm.com/docs/gitrevisions

Here's the example:

  $ git config push.default current
  $ git config remote.pushdefault myfork
  $ git switch -c mybranch origin/master
  $ git rev-parse --symbolic-full-name @{upstream}
  refs/remotes/origin/master
  $ git rev-parse --symbolic-full-name @{push}
  refs/remotes/myfork/mybranch

My setup looks like this:

  λ git -v
  git version 2.43.0
  λ git remote -vv
  myfork git@xxxxxxxxxx:heymatthew/dactyl-configurator-fork (fetch)
  myfork git@xxxxxxxxxx:heymatthew/dactyl-configurator-fork (push)
  origin https://github.com/rianadon/dactyl-configurator (fetch)
  origin https://github.com/rianadon/dactyl-configurator (push)

Here's what I get from running the documented example:

  λ git config push.default current
  λ git config remote.pushdefault myfork
  λ git switch -c mybranch origin/main
  λ git push
  * [new branch]          mybranch -> mybranch
  branch 'mybranch' set up to track 'myfork/mybranch'.
  λ git rev-parse --symbolic-full-name @{upstream}
  refs/remotes/myfork/mybranch
  λ git rev-parse --symbolic-full-name @{push}
  refs/remotes/myfork/mybranch

I was expecting @{upstream} to be origin/main, but it appears that @{u} and
@{p} are the same.

Am I doing something wrong?
Are there better examples someone can point me at to do this?

Thanks in advance :)

Ngā mihi,
Matthew