BUG: cannot remove new staged files in sparse checkout

Hi friends!

I've stumbled across what I believe is a bug

I've found myself with new files that are staged, not part of the
sparse-checkout, that I cannot unstage using git restore --staged, ie
  git restore --staged :\
does nothing.

I'm able to get rid of the using
  git stash && git stash drop
but intuitively I would expect restore --staged to work, even if the
files are not part of the sparse checkout

I end up in this peculiar situation by doing the following.
Having branches:
  foo/bar
  origin/foo
and then running
  git switch -c foo
Updatings files: 100% (X/X) done.
fatal: cannot lock ref 'refs/heads/foo': 'refs/heads/foo/bar' exists;
cannot create 'refs/heads/foo'

I should add this behavior was seen in
  git version 2.35.1.windows.2