No shopify session id cookie stored in browser

[GkPayments]

My store uses a custom checkout which captures shopify session id as the time checkout opens by accessing the cookie '_shopify_s' which is stored in the browser. However I am not able to detect this cookie stored on the cart page. 

^checking the cookie via console tab.

This function is executed when pages load in the liquid theme file which captures the shopify session id.

This probably does not seem to be a checkout issue. What can be the issue here?