x-for nested components not updating correctly

[geouser]

Noticed that when you have a nested component inside x-for loop - it does not update properly when data in the array changes. Here is the fiddle https://jsfiddle.net/serhiyhulyi/98k7x05w/. The quantity component here is just a placeholder, but it shows the problem - when you remove items from top to bottom the quantity doesn't update, which is strange, but if to remove items from bottom to top all seems ok.
Does anyone know how to solve this issue?

[geouser]

Ok, answering my own question - it says in the documentation that it is important to specify keys for each x-for iteration. Adding it solves the issue.