Trigger right after unmounting a field with shouldUnregister causes isValid to be true but errors still contains error

[csimomelian]

When I unmount a field using a local state toggle (open) and have shouldUnregister enabled on the Controller, calling trigger(name) immediately after unmounting leads to this unexpected behavior:

• isValid becomes true

• But the errors object still contains the error of the unmounted field

• Clicking submit does nothing (form doesn't actually submit)

This only happens if trigger("name") is called synchronously right after toggling the field's visibility. If I delay the call with setTimeout(() => trigger("name"), 0), the issue does not happen.

Steps to reproduce

1 - Render a field with shouldUnregister set to true

2 - Toggle its visibility off (causing unmount and unregister)

3 - Immediately call trigger("fieldName") (before next render)

4 - Observe that isValid === true, but errors still includes the field

5 - Try to submit — nothing happens

Expected behavior

When a field is unmounted and unregistered, calling trigger(name) immediately after should either:

Not trigger validation at all (because the field no longer exists), or

Trigger and clear any existing errors (since the field is no longer part of the form)

Also, isValid should reflect the state of errors.

Additional context

⚠️ The example provided here is a simplified version only meant to reproduce the issue.
In my actual project the setup is more complex and involves dynamically shown/hidden steps in a form wizard.
However, the core issue seems to stem from calling trigger right after unmounting a field that uses shouldUnregister.

Version: React Hook Form v7.x

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