Flask session behaves erratically

[Larz60+]

I setup my system to look like: https://github.com/miguelgrinberg/flasky
there is a video for this as well: https://www.youtube.com/watch?v=UXqiVe6h3lA

I'm not suggesting you go this route, but since I started using it, I have not had any problems.
Sorry I can't help you more, perhaps someone else will pick up here.