Validation is no longer working on useFieldArray fields

Describe the bug After upgrading to 7.X we are now experiencing problems with validation of fields inside useFieldArray.

When adding a new row of fields, the form is invalid no matter if the fields has been filled out correctly. Removing the newly added row, makes the validation true. Only filling out the default row makes the form valid, however, adding two rows and remove the default one makes the form invalid.

To Reproduce Steps to reproduce the behavior:

1. Go to https://codesandbox.io/s/romantic-ptolemy-nlgcc?file=/src/App.tsx
2. Fill out “Test” in "Name
3. Fill out “1” in Field 1 and “2” in Field 2
4. Notice the form is valid
5. Click “Add Row”
6. Notice the form is invalid
7. Fill out “3” in Field 1 and “4” in Field 2
8. Notice how the form stays invalid

Codesandbox link (Required) https://codesandbox.io/s/romantic-ptolemy-nlgcc?file=/src/App.tsx

Expected behavior The validation to form on dynamically added fields.

[janhartmann]

I was able to solve my problem in my application by not using a <Controller> around my input field (but registering directly on the input). I dont know if that helps you in any way, but I wanted to let you know. Thanks for an excellent library by the way.

[janhartmann]

I just tried upgrading, and the bug is still there. When adding a new list of fields, the form becomes invalid. Go to https://codesandbox.io/s/romantic-ptolemy-nlgcc?file=/src/App.tsx and change the version to 7.6.2