Vertical scrollbar not visible but working in domLayout ‘autoHeight’

I was previously using ag grid v28 and now migrated to ag-grid v32.
I am using domLayout as ‘autoHeight’ in my gridOptions.
And in my styling I was given around 250px for .ag-body-viewport and overflow-y: auto; as given below.

.ag-body-viewport {
  height: 250px;
  overflow-y: auto;
  overflow-x: hidden;
}

But after upgrading, the vertical scroll is working but the scrollbar is hidden.
Someone help

Previously the vertical scrollbar was visible with same code in v28, there is nowhere mentioned about this in their upgrade notes.

If I give scrollbar-width: thin ! important;
I am able to see the thin scrollbar, but I am expecting the old behaviour