*ngIf not working as expected with observable
Put the async pipe in parenthesis.
<a class="router-link nav-item" routerLink="/login" *ngIf="!(isLoggedIn$ | async)"> Login</a><a class="router-link nav-item" (click)="onLogout()" *ngIf="isLoggedIn$ | async"> Logout</a>
You can also refactor to use the else part of ngIf directive:
<a class="router-link nav-item" (click)="onLogout()" *ngIf="isLoggedIn$ | async; else loginBlock"> Logout</a><ng-template #loginBlock> <a class="router-link nav-item" routerLink="/login"> Login </a></ng-template>You can see more examples in the docs.