Disjunct selection per keyboard is not possible

AdvStrinGrid, selecting rows:
Expanding a selection with Shift+ArrowUp/Down works fine.

With Ctrl+ArrowUp/Down the grid is scrolled, but focus doesn't change;
focus should be moved, and disjunct selection should be possible with the Shift key.

Did I miss any setting to control this behaviour?

Thanks for reporting. We have seen an issue with this and we're investigating this.