material design not recognize

Here is my folder:

-app 
     -content
     -footer
     -header
       -main-header
         {other services - shortcut} <- I just shortcut this bec. it is too long.
         main-header.component.html
         main-header.component.scss
         main-header.component.spec.ts
         main-header.module.ts
         main-header.routing.ts
     app.component.html
     etc..

main-header module

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { MainHeaderComponent } from './main-header.component';
import { MainHeaderRouteModule } from './main-header.routing';
import { MatCheckboxModule } from '@angular/material/checkbox';
import { MatCardModule } from '@angular/material/card';
import { MatSidenavModule } from '@angular/material/sidenav';
import { FormsModule } from '@angular/forms';
import { LayoutModule } from '@angular/cdk/layout';
import { MatToolbarModule } from '@angular/material/toolbar';
import { MatButtonModule } from '@angular/material/button';
import { MatIconModule } from '@angular/material/icon';
import { MatListModule } from '@angular/material/list';

@NgModule({
  declarations: [
    MainHeaderComponent
  ],
  imports: [
    MatCardModule,
    MatCheckboxModule,
    MatSidenavModule,
    FormsModule,
    LayoutModule,
    MatToolbarModule,
    MatButtonModule,
    MatIconModule,
    MatListModule,
    MatCardModule,
    MainHeaderRouteModule,
    CommonModule
  ]
})
export class MainHeaderModule {}

main-header.routing

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { MainHeaderComponent } from './main-header.component';


const routes: Routes = [
  {path: '', component: MainHeaderComponent}
];


@NgModule({
  imports: [RouterModule.forChild(routes)],
  exports: [RouterModule]
})
export class MainHeaderRouteModule {}

app module

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { MainHeaderComponent } from './header/main-header/main-header.component';


@NgModule({
  declarations: [
    AppComponent,
    MainHeaderComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    BrowserAnimationsModule
  ],
  exports: [
    MainHeaderComponent
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

app.routing.module

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';


const routes: Routes = [
  {path: '', redirectTo: 'main-header', pathMatch: 'full'},
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

Since I am using a lazyloading route, it seems that the main-module doesn’t recognize angular material:

‘mat-sidenav-container’ is not a known element:
1. If ‘mat-sidenav-container’ is an Angular component, then verify that it is part of this module.
2. If ‘mat-sidenav-container’ is a Web Component then add ‘CUSTOM_ELEMENTS_SCHEMA’ to the ‘@NgModule.schemas’ of this component to suppress this message. (“[ERROR ->] Source: New feed
Source Url material design not recognize