Problem with angular flex-layout - doesn't show current tab

Question

I have code in Angular, i am using angular flex-layout but it doesnt work on big screen. When i am changing tab it'doesnt show. It shows when I am refreshing the site.

    <div fxShow="true">
  <div class="body">
    <mat-drawer-container class="example-container" fxHide.lt-md>
      <mat-drawer mode="side" opened>
        <mat-toolbar>
          <mat-toolbar-row>
            <span>MENU</span>
          </mat-toolbar-row>
        </mat-toolbar>
        <div fxShow="true" fxHide.lt-md>
          <div class="nav" style="display:flex;flex-direction:column;">
            <a routerLink="/new-invoice">New Invoice</a>
            <a routerLink="/preview-invoice">Preview Invoice</a>
          </div>
        </div>
      </mat-drawer>
      <mat-drawer-content>
        <mat-toolbar color="primary">
          <mat-toolbar-row>
            <h1>KLG invoice generator</h1>
          </mat-toolbar-row>
        </mat-toolbar>
        <div class="route">
          <router-outlet></router-outlet>
        </div>
      </mat-drawer-content>
    </mat-drawer-container>
    <!-- NA DOLE Mały EKRAN U GORY duży-->
    <div class="body2" fxHide.gt-sm>
      <mat-toolbar color="primary">
        <button class="menu-button" mat-icon-button (click)="sidenav.toggle()" fxShow="true" color="primary">
          <mat-icon>menu</mat-icon>
        </button>
        <span>KLG invoice generator</span>
      </mat-toolbar>
      <mat-sidenav-container fxFlexFill class="example-container">
        <mat-sidenav #sidenav fxLayout="column">
          <div fxLayout="column">
            <a routerLink="/new-invoice">New Invoice</a>
            <a routerLink="/preview-invoice">Preview Invoice</a>
          </div>
        </mat-sidenav>
        <mat-sidenav-content fxFlexFill>
          <div class="route">
            <router-outlet></router-outlet>
          </div>
        </mat-sidenav-content>
      </mat-sidenav-container>
    </div>
  </div>
</div>

Someone can help me ? I don't have any errors with routing and tab is changing after refresh so I guess that's the problem with my layout.