title: Service is called multiple times inside NgRx Effect
body: <p>When I dispatch an action, service is called more than one time inside effect and I have to use &quot;exhaustMap&quot; instead of &quot;concatMap&quot; or &quot;mergeMap&quot; in all effects every time, and I do not know how it happened suddenly because it was OK before.
  And I know that I do not dispatch one action before one time but it calls the service more than one time (in this case two times).</p>
  <p>I imported effect in contact module like this:</p>
  <pre><code>EffectsModule.forFeature([PersonalContactEffects]),
  StoreModule.forFeature(personalContactFeatureKey, personalContactReducer)
  </code></pre>
  <p>and the Effect is:</p>
  <pre><code>        loadPersonalContacts$ = createEffect(
          () =&gt; this.actions$.pipe(
              ofType(personalContactActions.loadPersonalContactsList),
              tap(action =&gt; console.log(&quot;before service call&quot;, action)),
              concatMap(action =&gt; this.contactService.getList(action.query)),
              map(personalContactList =&gt; personalContactActions.personalContactsListLoaded({ personalContactList })),
              catchError(() =&gt; of(personalContactActions.setLoading({ loading: false })))
          )
      );
  </code></pre>
  <p>and I dispatch this action like this:</p>
  <pre><code>this.store.dispatch(fromPersonalContactActions.loadPersonalContactsList({ query }));
  </code></pre>
  <p><a href="https://i.stack.imgur.com/iAPS8.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iAPS8.jpg" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/SwGWm.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SwGWm.jpg" alt="enter image description here" /></a></p>