Why are rxjs pipe() operators not included in code coverage reports?

Question

The Problem

rxjs map() is not included in istanbul code coverage report, despite the lines being tested. The other questions related to this cover http-testing, which this isn't about. I need to either find a way to test pipes or exclude statements inside pipe() from coverage reports.

Description

I have an Akita entity store and query for vehicles. Based on some settings a vehicle can use either frontendLocation if it exists or CurrentLocation (naming is not up to me).

vehicle.query.ts

export class VehicleQuery extends QueryEntity<VehicleState, Vehicle> {
    /** Returns an observable<number[]>, e.g. [50, 50] */
    location$ = this.selectActive().pipe(
        filterNil,
        map((v) => v.frontendLocation || v.CurrentLocation), // This is shown as not covered 
        distinctUntilChanged(_.isEqual)
    );
    // ...constructor etc.
}

In my spec file I set an active vehicle with a frontendLocation and test that the query:

1. Gets the frontendLocation of the vehicle if it exists
2. Gets the CurrentLocation of the vehicle if frontendLocation doesn't exist.

describe('VehicleQuery', () => {
    const vehicle = { ...otherAttributes, frontendLocation: [50, 50], CurrentLocation: [49, 49] };
    let query: VehicleQuery;
    let store: VehicleStore;
    beforeEach(() => {
        TestBed.configureTestingModule({
            providers: [VehicleQuery, VehicleStore],
        });
        query = TestBed.get(VehicleQuery);
        store = TestBed.get(VehicleStore);
        store.add(vehicle);
        store.setActive(vehicle.Id);
    });
    describe('location', () => {
        it('Returns frontendLocation of current vehicle if it exists', () => {
            query.location$.subscribe((s) => {
                expect(s).toEqual([50, 50]);
                expect(s).not.toEqual([49, 49]);
            });
        });
        it("Returns CurrentLocation of current vehicle if frontendLocation doesn't exist", () => {
            store.updateActive({ frontendLocation: null });
            query.location$.subscribe((s) => {
                expect(s).toEqual([49, 49]);
                expect(s).not.toEqual([50, 50]);
            });
        });
    });

This covers both options inside the query's location$ pipe. Both tests pass, but the map() on line 4 of the query still shows up as not covered.