field array loses values using Controller

To Reproduce Steps to reproduce the behavior:

1. Go to https://codesandbox.io/s/react-hook-form-usefieldarray-nested-arrays-forked-78qdb?file=/src/fieldArray.js:665-670
2. Click “Append”, enter any text
3. Click “hide” button and then “show”
4. See default values in text input

If I use register instead of Controller everything is fine.

Codesandbox link (Required) https://codesandbox.io/s/react-hook-form-usefieldarray-nested-arrays-forked-78qdb?file=/src/fieldArray.js:665-670

[bluebill1049]

I am going to roll back this fix guys, as this is breaking a deeply nested field #4941 https://github.com/react-hook-form/react-hook-form/issues/4941, so to work around this issue.

let me explain the problem because useFieldArray needs defaultValue as the initial input state. Toggling input doesn’t really change the defaultValue stored in useFieldArray resulted in the above issue.

https://codesandbox.io/s/react-hook-form-usefieldarray-nested-arrays-forked-31soo

so work around this issue for toggling input, you can use getValues to set the defaultValue, well I know this is not convenient, but it’s about to cover all use cases, and I hope for your understanding. also you can use useWatch API for the individual’s defaultValue as well.

https://codesandbox.io/s/react-hook-form-usefieldarray-nested-arrays-forked-ez7un?file=/src/fieldArray.js

I have also included a new section in the doc:

[shestakov-vladyslav]

This is very unobvious 🙁 And I can’t find this information in documentation