BUG: indexing bugs #26490, #13691
- [x] closes #26490
- [x] closes #13691
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Closing in favor of #37161, #37152