Customer can't register an account during order process

Question

I am setting up a new multi-store Magento 1.9.3.3.

Problem:
If the customer wants to register a new account during the order process (onepage-checkout), the account won't get created in the DB. The order getting placed neatly but not the customer account itself.

No errors or exceptions are thrown concerning this issue.
But when I create directly an account in the frontend without processing an order, it works.

I am using a custom template. Apparently it don't touches the process. Aswell other extensions, as far as I can say.
Does someone have perhaps a clue to look for or an idea what could cause this issue?

Answer 1

i think it is the latest issue in magento.

please refer to this. https://magento.com/security/patches/supee-9767

and this. SUPEE-9767 Patch/CE 1.9.3.3 - One Page Checkout - Customer Registration issue