Not sure whether this is frontend or backend related, so I selected both components.
When I select "New order workflow" and Task C as a Flow node filter, I get 14 results. Once I select all of them and create a new selection, this selection is shown on the UI to consist of 38 Instances (see screenshot). I expect the selection to consist of exactly 14 instances in this case. Please investigate.
Update: when not selecting a flow node filter but a workflow, then the number shown in the badge on the selection always is 527, no matter which workflow i selected.