Cart change API not working for items already in cart

[haripraneshHP]

POST /cart/change.js API is not working when I try to increase the quantity of the items already present in cart.

The API response is successful but after clicking checkout button I couldn't see the updated quantity for the line item in checkout page.

This issue is happening only when I call the POST /cart/change.js API from cart page. POST /cart/change.js API is working perfectly when I try it from product page or home page. 

I have also tried POST /cart/add.js, POST /cart/update.js APIs but I'm facing the same issue.