I ran into a little problem with my newest WP and woocommerce installation.
After the checkout, I see the message "Sorry, your session has expired". First I thought it could be a problem with plesk or php, but sessions do work.
After digging in the code and with help of F12, I found, that the woocommerce wp_ajax hook does delete/ invalidate the cart_has_items_cookie and the global $woocommerce is therefor empty (except the adress?). The duration of all cookies is set to session and they are working just fine.
There is more than one WP installation on this machine, and none of them has any problems regarding sessions.
I am out of ideas ...
Any help would be greatly appreciated.