Probably you are working on app that is similar to our demo app. There is no such a problem. So, you may learn this example and possibly it will help to solve the issue:
When you change value of counter button, this value is kept in list datastore. However, if you reload list data, all list item are replaced with data from data source you load. So, please check whether data that you load contains correct count values.
If the problem can not be solved, you can attach a demo that reproduces it.
There was incorrect setTotal method in your app. The sum was started with 0 value and only filtered items were calculated.
But, in my opinion, you will need more information about ordered items in order app: at least item id and ordered count. We have modified your ts_main.js and add DataCollection to store ordered items (changed counterClick and setTotal methods). Each time you click on “counter” button, order collection is updated (an item is added, updated with new count or removed). ts_main.zip (2.76 KB)