Angular primeng v11.x setting scroll height to p-tree not displaying scroll

Question

i am using primeng v11.x and using p-tree to display hierarchy values. As the list is quite big, i want to fix a height. i am using following but the scroll bar not appearing in the p-tree.

<div class="tree-component">
    <div>
            <p-tree
                #tree
                [value]="nodes"
                selectionMode="checkbox"
                [propagateSelectionUp]="true"
                [propagateSelectionDown]="true"
                (onNodeUnselect)="onNodeUnselect()"
                (onNodeSelect)="onNodeSelect()"
                disabled="disabled || readonly"
                scrollHeight="200px"
                [virtualScroll]="true"
            ></p-tree>
        </div>
</div>