Selecting multiple graphs in IGV and then clicking the red cross to delete them altogether works as expected. However, once the "Expand the difference selection" is used on a graph, it does not anymore: It only deletes a single graph instead of all selected graphs.

To reproduce:
1) Import any XML graph file
2) Open any graph
3) Click "Expand the difference selection" button in the toolbar
4) Select multiple graphs
5) Click the red cross above to remove the graphs ("Remove selected graphs and groups" button)