I've tried the example from CodeSandbox here and I notice a strange behavior.

If I just use the example as it is then the "Add Child" button work properly.

But if I move the "Add Child" button to the parent component but still keep the "useFieldArray" in the "ChildForm" to render the array, then it doesn't work. There is no new field being create when I click on "Add Child"

Here is the new code

Is this a bug or is this something that is intended.

There is a feature that I'm working on the require me to have the parent component the append to the array and the child component to display it.
Right now I need to workarouond it by passing the "fileds" from the parent to the child with out using Lens.
Then my prop will be of this type which is not very nice