Python PIP package installed not importing

I have created a package via Github's pip instance, it is successfully installed:

    Running setup.py install for lsm-shared ... done
    Successfully installed lsm-shared-0.1.0

    % pip list | grep shared  
    lsm-shared                0.1.0

If I start python and manually import it then it works fine:

% python
Python 3.9.6 (default, Jul  5 2021, 01:04:38) 
>>> import lsm_shared

If I try and use the package in a project I get:

% quart run -p 3030
File "Development/lsm/servie/service/application.py", line 8, in <module>
import lsm_shared
ModuleNotFoundError: No module named 'lsm_shared'

The only difference between running manually and in a project is that I set PYTHONPATH, I don't know if that makes any difference.

I have looked at other solutions, including this StackOverflow question, and done the pip install with --user to no avail.