conditionnaly displayed FieldArray not reflect form values (seems de sync)

### Are you submitting a **bug report** or a **feature request**?
a bug report

### What is the current behavior?

I use a pattern that rely on a Field to conditionnaly show / hide a FieldArray
It appear that the field array wrapped inside a condition are not in synch with the form values

You can check a different flavour of the bug by removing the initialValues in my exemple

### What is the expected behavior?

The field Array should reflect the form values

### Sandbox Link

https://codesandbox.io/s/react-final-form-field-arrays-nbh7d

### What's your environment?

the problem appears after I bump react-final-form from 4.1.2 to 6.3.0

hope it helps !