arrayfield item index as key - fails to update

[tzookb]

on Formik docs for ArrayField:
https://formik.org/docs/api/fieldarray

we render the items with key={index}

but when I remove one of the items, the view is not updated properly, because react thinks the item didnt change as the index didnt change.

so if I have:

• index: 0 , value: hey
• index: 1 , value: bye

I remove the item at index 0, then I have

• index: 0, value: bye

react will still show "hey" instead of "bye"