Angular child page refresh redirects to root

The problem regards routing in an Angular 13 app which is divided in few components.
Components hierarchy is something like this:

• User (root)
  • Child 1
    • Child 1-1
  • Child 2

The root component is under the /u url so it’s renderized when you go to localhost:4200/u. Its html contains a simple menubar which has buttons that redirects to child components (all of them works correctly, no problems at all) and contains a router-outlet so that they can be renderized internally.
The problem comes when I’m, for example, on Child 1-1 and I refresh the page. What happens is that Angular routes to /u/child-1/child1-1 but soon after it routes to /u.
This issue also doesn’t make possible for me to access the app directly from /u/child-1/child-1-1 which is a big problem because I need it.

Routes are configured correctly (otherwise routing from /u to its children wouldn’t work correctly which does) but I’ll report them just in case:

user.route.ts:

const children: Routes = [
  child1Route,
  child2Route,
];

export const USER_ROUTE: Route = {
  path: 'u',
  component: UserComponent,
  data: {
    pageTitle: 'user.title'
  },
  canActivate: [AuthGuard], //disabled
  children: children
};

export const USER_ROUTES: Routes = [USER_ROUTE];

child1.route.ts

const children: Routes = [
  child1-1Route
];

export const child1Route: Route = {
  path: 'child1',
  component: ChildOneComponent,
  children: children
}

child1.route.ts

export const child1-1Route: Route = {
  path: 'child1-1',
  component: ChildOneOneComponent,
}

USER_ROUTE is then inserted into RouterModule.forRoot(USER_ROUTE) in user.module.ts (but again, is not our concern because if roots were bad configured it wouldn’t have worked at all). I didn’t report child2 routes because they are useless for this purpose.

Has anyone ever experienced something like this? How can I understand what is going on?

The only thing I tried succesfully was to listen for url changes in user.component.ts and redirect to /u/child-1/child-1-1 whenever someone went to /u but as you can imagine this is very dirty because I can’t use /u anymore if I do it like this.