1. Open https://staging.infragistics.com/products/ignite-ui-blazor/blazor/components/grids/tree-grid/cell-selection
2. Navigate to the "Tree Grid Multiple-Cell Selection" sample.
3. Examine the "How to select cells:" -> Clicking with the Left Mouse key while holding CTRL key will add single cell ranges into the selected cells collection.

Using this combination doesn't do anything in the sample.