Angular Mat Side navigation bar issues when content is huge and footer issues

I am using Material side navbar and I am facing issues when the content is huge and my footer is displaying in odd places. guide me in this

navbar Html:

<mat-sidenav-container autosize &gt
  <mat-sidenav #sidenav="matSidenav" class=""   opened="isExpanded" >
    <mat-nav-list>
      </mat-nav-list>
  </mat-sidenav>
  <mat-sidenav-content>
    <mat-toolbar class="mat-elevation-z2 ">   <button
      mat-icon-button
      *ngIf="sidenav.mode === 'over'"