null errors pop up in dev mode

[JohnCido]

Sometimes when I resize web page in dev mode, bunch of null errors pop up. The amount of errors changes after I refresh the page. And the whole webpage flash white when the width of the webpage is lower than certain threshold, and that threshold changes after a refresh too.

You can see the error log in this screenshot:

The last line of each following code blocks is the line marked by Chrome DevTool in source.

export function DevOverlay(props) {
    ...
        console.error(error);

export function DevOverlay(props) {
    ...
            pushError(error.error);

export function DevOverlay(props) {
    ...
        window.addEventListener("error", onErrorEvent);

function runComputation(node, value, time) {
  ...
    nextValue = node.fn(value);

function updateComputation(node) {
  ...
  runComputation(node, Transition && Transition.running && Transition.sources.has(node) ? node.tValue : node.value, time);

function runTop(node) {
  ...
      updateComputation(node);

function runUserEffects(queue) {
  ...
  for (i = 0; i < userLength; i++) runTop(queue[i]);

function completeUpdates(wait) {
  ...
  if (e.length) runUpdates(() => runEffects(e), false);else DevHooks.afterUpdate && DevHooks.afterUpdate();

function runUpdates(fn, init) {
  ...
    const res = fn();

function completeUpdates(wait) {
  ...
  if (e.length) runUpdates(() => runEffects(e), false);else DevHooks.afterUpdate && DevHooks.afterUpdate();

function runUpdates(fn, init) {
  ...
    completeUpdates(wait);

function createRoot(fn, detachedOwner) {
  ...
    return runUpdates(updateFn, true);

function render(code, element, init, options = {}) {
  ...
  createRoot(dispose => {

function hydrate$1(code, element, options = {}) {
  ...
  const dispose = render(code, element, [...element.childNodes], options);

const hydrate = (...args) => {
  enableHydration();
  return hydrate$1(...args);

export function mount(fn, el) {
  ...
    return hydrate(fn, el);

mount(() => <StartClient />, globalThis?.document?.documentElement)

Could it be a effect related error since I can see runUserEffects in the code?

It's just that null error made it impossible for me to find out the true cause.