Accessibility issue on Mat-chip-list- aria attributes does not match their roles

Question

For mat-chip-list as per the document the aria-role for chiplist as listbox with each chip has option as role,even I gave those two role as mentioned in the below code,

<mat-chip-list #chipList role="listbox" aria-label="filtervalues">
    <span *ngFor="let x of values">
      <span *ngFor="let y of x.items">
        <mat-chip role="option">y</mat-chip>
      </span>
    </span>
</mat-chip-list>

unable to attain 100% accessibility,shows "aria attributes does not match their roles".How to overcome this error?