Koito/client/app/entry.client.tsx

import { startTransition, StrictMode } from "react";
import { hydrateRoot } from "react-dom/client";
import { HydratedRouter } from "react-router/dom";

startTransition(() => {
  hydrateRoot(
    document,
    <StrictMode>
      <HydratedRouter />
    </StrictMode>
  );
});