Loader synchronization failure in nested route hierarchies

Direct Answer

Yes, a search-parameter change at the parent level triggers a navigation event that re-executes loaders for all matched routes, including nested children—provided each child declares its own loader. If a child route has no loader, it simply inherits the parent's data and will not fetch independently.

Confirmed Behavior

• Any navigation that changes pathname, search, or hash causes React Router v6 to re-run loaders for every route in the matched hierarchy.
• This is not a full page reload; it is an internal navigation that preserves component state while refreshing data.
• A child loader receives the updated request.url (including the new search params) automatically—no extra wiring is required.

Mechanisms to Force Synchronization Without a Full Reload

1. Standard Navigation (Recommended)

// In a parent component
import { useNavigate } from 'react-router-dom';

const navigate = useNavigate();
const updatePage = (page) => {
  navigate('?page=' + page + '&limit=20', { replace: true });
};

Calling navigate with updated search params and replace: true pushes a new location, triggering the normal loader cascade.

2. Targeted Child Reload with useFetcher

import { useFetcher } from 'react-router-dom';

const fetcher = useFetcher();
const refreshChild = () => {
  fetcher.load('/parent/child'); // child route path
};

Use this when you want the child to refetch without changing the URL or affecting the parent's loader.

3. Opt-In Revalidation via shouldRevalidate

// Route config
export const shouldRevalidate = () => true; // runs on every navigation

Forces the loader to run even when its own params haven't changed. Use sparingly—it can cause unnecessary fetches.

Verification Steps

1. Add console.log('child loader', request.url) inside the child loader.
2. Trigger a parent search-param change (via navigate or a <Link>).
3. Confirm the child log appears with the updated URL.
4. If it does not, verify the child route actually exports a loader function.

One Diagnostic Detail Needed

Does the child route export a loader function? If not, add one (even a thin wrapper that calls the API with the parent's params) to participate in the synchronization.