Not sure if anyone is still on this list but I'll give it a shot...
I still have a customer on Satchmo (they haven't been willing to pay for a rewrite to something else). Naturally they have had problems with old TLS on their payments provider. I moved them to ActivePython 2.6 and the gunicorn server that comes with it. That has TLS 1.2 and works beautifully.
But one in a while, a customer will look at his cart, hit the checkout button, and step 1 of checkout says "your cart is empty" and it's only obviously not. Restarting gunicorn fixes it.
I looked at the code and it stores the cart in the user session and in step 1 gets it back out. So it seems to lose it.
Anyone see this before (with or without Satchmo)? Is something with gunicorn causing it to fall out?