Cashier product search autocomplete field stops working when Varnish in use

I'm facing a similar issue, but not only with varnish. I have the issue under varnish and nginx. I think we are not setting cookies properly in this module. Here are the two occurrences of setcookie:

setcookie($this->cookieName, json_encode($this->cashiers),
      time() + $this->cookieDuration, '/');

setcookie('commerce_pos_register', $register->id(), time() + 31557600, '/');

In my opinion we should be setting them as HttpOnly and Secure:

setcookie($this->cookieName, json_encode($this->cashiers),
      time() + $this->cookieDuration, '/', '', TRUE, TRUE);

setcookie('commerce_pos_register', $register->id(), time() + 31557600, '/', '', TRUE, TRUE);

This way the cookies persist across requests.

I'm not exactly sure if we are facing the same issue. So sorry in case I'm hijacking this issue.

This patch fixes the issue for me.

Ok, I understood why we are using cookies: We want to store this data across multiple session on the same device.