When I try to click add to cart very fast like add item A then, B immediately.. Many time, item A will not really add to cart. If it's just that, it would be ok. But I found out later that item A is there in the cart. The Order activity log shows that item A is added but not show up in the list of item added in the cart. Here is what I found in database:
- disappeared item A is there in commerce_order_item table
- commerce_order__order_items don't have that disappeared item A.
Click "add to cart" very quickly.
Closed: works as designed
1.0
Code
In my case, I just found that I have some ECA model that cause this problem. So, it's not problem with Commerce Core or any Ajax cart modules.