router state selectors return undefined... unless in component

[moniuch]

I have been struggling with a case which is almost an exact copy of 835: same intention of combining router selectors with other selectors. Unfortunately, none of the tips mentioned there solve my problem, however I made a small discovery and I would hope for someone in the know to explain it to me what is exactly happening, please.

I am trying to combine the entities from a lazy-loaded admin feature, with the route params, to display the currently accessed user entity.

router.selectors

export const getRouterState = createFeatureSelector<RouterReducerState<RouterStateUrl>>(ROUTER_STATE_KEY);

export const getRouterStateParams = createSelector(
	getCurrentRoute,
	state => {
		console.log('getCurrentRoute router.selector', state);
		return state.params
	}
);

user.selectors.ts

export const getUserFromRouteParam = createSelector(
	selectEntities, // from entity adapter
	fromRouter.getRouterStateParams,
	(entities, params) => {
		console.log(entities, params)
		return entities[params['id']]
	}
)

This selector fails because of params being undefined. Alongside, there is a console warning saying that the feature name 'router' does not exist in the state (although it does exist)...

However when I bring this very selector directly into my component, like so:

this.params$ = this.store.select(fromRouter.getRouterStateParams)

I get a beautifully populated state, just as expected, and the warning is not there.

I would like to understand what is happening here.
Of course, as a workaround, I could combineLatest those two selectors in my component, but I would prefer to move it down to the ngrx selector layer (architecture, memoization) and rather understand how to make it work.

Why is it that a selector from router store doesn't work within another selector but does work on its own. Is it a race condition? What can I try?