Controller not updating value on change.

[nikhilkpn01]

I am using useFieldArray for a nested form. Were I fill the array with some default values. I need to change the value of the field based on index.
It works when I use "input" with 'register' but not working with 'Controller'.
Please find https://codesandbox.io/p/sandbox/usefieldarray-yz5yjs?file=%2Fsrc%2FApp.js%3A8%2C10
When I click on 'change' button both the fields should change.

Can someone help me to fix this issue?

[Moshyfawn]

I'm a bit confused about the use case here, so bear with me. I see you're registering a field array, but not using its API. By updating the index value in the name, you create 2 fields with the same name, which results in the last field with the name being registered as a field, overriding the behaviour of the one before it due to the order of operations. This wouldn't work.

[nikhilkpn01]

It's just an example.
If you remove NestedWithoutController component it still won't work.
My use case is:
I have a deep nested form with more than 2 layer. Suppose I have,
defaultValues: { students: [ { name: '', subjects: [ { name: '', mark: null } ] } ] }
And I keep only one form for filling single student details. After filling I can append another one and current form will be collapsed.

Like the one used in antd. At a time I can edit/create a single student.
My requirement is when I pass the index I want to open the form in edit mode so that I can update it.