wordpress+nginx=cart not working???

Hello..

I have a huge problem with my worpress woocommerce website.
Some developer moved me from apache to nginx and the diffrence in speed was amazing.
The problem is that for some reason my cart is not working properly and i cant find right now the developer and i dont know what did he changed.
The 1st problem is that you can add products only from the 1st page, but if you go to cart page At the bottom the radio buttons are dead.
check for your self.
The other problem is that my filters stoped working too (i think this for some reason the cart and the filters are related)

I dont know what is happend but i need a help from you guys.
Can you direct me why is this happening ? Is it something about rewrite rules ?
Can i check something to fix it ?

I have Centos 7 minimal
Latest Webmin/Virtualmin
Latest nginx
check my site: thikishop.gr

Thank you.
Kostas