Width of custom headers in ag-grid (angular) doesn't match with column's width

Question

I have a custom component that implements both ICellRendererAngularComp, IHeaderAngularComp. It is to be used both as a cell and header. However, when the component is rendered as a header, It doesn't span across full width.

colDefs: ColDef[] = [
    {
      field: "Text",
      headerName: "Text",
      headerComponent: GridCellComponent,
      headerComponentParams: {
         .....
      },
      cellRenderer: GridCellComponent,
    },
]

I found a similar question here, But the solution mentioned doesn't seem to work now. Please ask if you need any specifics related to problem.