Hi,
Changing the WP_Query order is not going to do anything, since the plugin uses it’s own ordering, which you can set under the General Options -> Ordering panel here: https://i.imgur.com/qlxy8So.png
When using the auto-populate with the latest results, then the ordering will be forced as date descending of course. If you want to have the default order (as set on the ordering panel), then use the auto-populate for an empty phrase instead: https://i.imgur.com/O7uUDit.png
The programmatical query arguments ordering change was probably not working for the same reason for the auto populate. The ordering parameter is the $args['post_primary_order'] and the $args['post_secondary_order'] variables.