Why does ng2-semantic-ui multi-select show "No results"?

Question

I have a filter function for my table. Previously I was using suiDropdown and it is working fine.

I want to change it to multi-select so I used sui-multi-select. But why does it show "No results"?

suiDropdown:

<div class="ui dropdown" suiDropdown>
        <div class="text">雇用区分</div>
        <a><i class="dropdown icon"></i></a>
        <div class="menu" suiDropdownMenu>
            <div class="item" name="clear" (click)="onSelectFilter('category', '')">クリア</div>
            <div class="item" *ngFor="let cat of categories" (click)="onSelectFilter('category', cat)">{{cat}}</div>
        </div>
</div>

sui-multi-select:

<sui-multi-select class="selection"
                    [(ngModel)]="empCategory"
                    [options]="categories"
                    [hasLabels]="false"
                    [placeholder]="'クリア'"
                    (focusout)="onSelectFilter('category')"
                    #multiCateg>
        <sui-select-option *ngFor="let cat of multiCateg.filteredOptions"
                            [value]="cat">
        </sui-select-option>
</sui-multi-select>

Bottomline: suiDropdown displays the categories but sui-multi-select just shows "No results"