If you have a TextFormField with a validator in a Form with autovalidate set to true, the validator is not evaluated when the form field is first created, but it is evaluated the next time the Form builds, even if that happens for unrelated reasons (e.g. an animation, or a reassemble during hot reload). So for example this means that hot-reloading an auto-validate form will make all the validators trigger and all the text fields turn red.

cc @HansMuller