React hook form watch firing when inputs haven't changed - react-hook-form

Question

With react hook form, I am using watch to detect when inputs change, and remove errors as soon as an input change is detected...
const [authError, setAuthError] = useState<string>("");
const watchFields = watch(["email", "password", "confirmPassword"]);
useEffect(() => {
setAuthError((error) => {
console.log("use effect error value = ", error);
return error ? "" : error;
});
console.log(watchFields);
}, [watchFields]);
The problem is this code is always setting the error and then immediately resetting to an empty string. Below is the log whereby I:
set the email input to one already registered
set password and confirm password, and then hit submit
The error is correctly being set to Email address in use
['somit#somit.co.uk', '11111111', '11111111']
['somit#somit.co.uk', '11111111', '11111111']
use effect error value =
use effect error value =
POST https://... 400
['somit#somit.co.uk', '11111111', '11111111']
use effect error value = Email address in use
use effect error value = Email address in use
['somit#somit.co.uk', '11111111', '11111111']
use effect error value =
use effect error value =
But then it is being overridden as for some reason the watchFields triggers again - even though the inputs haven't changed. Am I trying to use watch incorrectly?