After a great deal of digging around I found a workaround in another post.
That is, for windows, to have a cell with,
import sys
sys.path.append(“…”)
I also had to restart the kernel.
Perhaps, I am missing something, but I would’ve thought that using other modules from within your own library would be fundamental need. So, it seems surprising that there is not a standard way of doing it, or the workaround is not documented. It would save people a lot of time. 