I read all the notes and forum posts, and I installed the last version of Python 3.6 (update 15). This doesn't work for me, and I'm tired of troubleshooting it!! (...ugh...)
I'm glad it works for some (congrats), but if it is this "picky" and inconsistent, then it is very likely to not work with a future O365 update. So, I'm cancelling this, and considering it "not worth it". If anyone else see this, best luck to you - but don't be surprised if you have errors. You have to use a old/outdated version of Python, and then hope that it works with new versions of O365 PowerPoint.
To the author: Thanks for trying, but this isn't a good solution and is *way* to inconsistent.