Status does not switch from created to confirmed

We are using authorize.net and everything works fine, except the status does not automatically switch from created to confirmed when an order is paid. When we switch the status manually after payment, the email is being sent. Is there some setting we have missed?

Thanks,
George.

I suppose that you're using authorize.net in SIM mode.
That means that after the payment is done, authorize.net is contacting HikaShop in order to confirm the order.
If the orders are not confirmed, it means that authorize.net servers were not able to contact HikaShop.
That can happen for several reasons, which are all listed here:
www.hikashop.com/en/support/documentatio...or.html#notification