BUG: columns name retention in groupby methods
- [x] closes #41564
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [x] whatsnew entry

is there an issue for this? > is there an issue for this?

No, though I _think_ it fixes #41564 checked and this does close #41564, will update above @meeseeksdev backport 1.3.x Something went wrong ... Please have  a look at my logs.