Jupyter loads python kernel instead of R kernel

Hello,
I'm cross-posting here in case the jupyter repo is not the correct place. Details are in this issue. I can't get the correct kernel to load when I start a notebook, this solution (installing ipykernel in the environment or base conda) is not working unfortunately: https://github.com/jupyter/notebook/issues/2563
Original github issue:
https://github.com/jupyter/jupyter/issues/397

Any help/advice is appreciated!

Start by reading the referenced issues in jupyter/notebook#2563 and jupyter/jupyter#397, then determine whether the reported kernel-selection problem still reproduces in the current Jupyter Notebook. A useful result would include current reproduction details and identify the relevant project or configuration responsible.

Written by the indexing model from the issue text.