Should do! I just tested it too and you’re right, it just sorts them by rank… very weird.
I think the sort function is mainly to be used with the First or Last function, as opposed to setting ui. You can’t set custom sort or filters on lookup fields (with ui) so I assume they just default to sort by rank without respecting the formula sort.
I think it’s a bug/issue.
Workaround would be to add a relation. Then either auto-link or just use the window to show context filtered tasks (from the person relation. But you would need to change the relation type to to-many because context filters only work with that at the moment i think… or just auto-link…) Then you can filter and sort by UI. And you have more control of the views.