Logout & Delete Cart Produscts After Refresh

Hello everyone, i have a issue with my shop.

Recently i switcht the server to nginix microcache. If i don't use the microcache everything is ok, but when i have 2000 ip's on website, become very very slow ... !

Everything is good, super speed BUT i have a super problem.

After a user is login in his account, add some products in cart and when si comeback to index , lost all products from cart and is logged out from his account.

I think is a session problem !

Is there anyone who can help me.


Cs Cart version : 4.7.2 sp2