Dates does not becomes dirty

[webartoli]

Describe the bug
Changes on date field make the form dirty but are not listed on dirtyFields props

To Reproduce

1. Send form (form is not dirty)
2. Change BirthDate Value
3. Send form (form is dirty but no field seems dirty)
4. See logs on console

Codesandbox link (Required)
https://codesandbox.io/s/react-hook-form-controller-template-ok-5iy6b?file=/src/index.js

Expected behavior
dirtyFields should contains {BirthDate: true}

Desktop (please complete the following information):

• OS: Windows 10
• Browser: Chrome
• Version 86

Additional context
In addition, The first form submit does not trigger any form dirty status