isValid is sometimes false despite no errors

Describe the bug I sometimes get isValid = false despite having no visible errors and errors object being an empty object ({})

To Reproduce I do not yet have a reproducable sandbox, but I already found a code piece that might be the problem. Please see additional context

Expected behavior isValid should always reflect what the errors object contains (e.g. isValid = Object.keys(errors).length === 0)

Desktop (please complete the following information):

• OS: Windows 10 202001
• Browser: Microsoft Edge
• Version: 86.0.621.0 (Official build) canary (64-bit)

Additional context The problematic line could be this code piece here: https://github.com/react-hook-form/react-hook-form/blob/03216edb0b29bae631fb752e6ec612111d82798d/src/useForm.ts#L341 which triggers revalidation but without providing an isValid parameter as the 4th parameter. Hence this line https://github.com/react-hook-form/react-hook-form/blob/03216edb0b29bae631fb752e6ec612111d82798d/src/useForm.ts#L218 will resolve in !!isValid which essentially means !!undefined === false.

AFAIK the problem only appears on async filled inputs (inputs that get their value via an api request).