Could be that your system default pip/python is not the one that is used by pycharm.
It’s been a long time since I’ve used pycharm, but they have a doc which talks about managing python packages from within it. Have you reviewed this? Install, uninstall, and upgrade packages | PyCharm
Thank you so MUCH! That link solved my problem, and the instructions are quite clear. Anyone else following that link notice that is says you need to download PyCharm 2021.1. Thanks to all on this great list who tried to help me.