Hi,
Thank you for all the details. Currently, I see you use the ‘ajax_sorting_order’ custom field for ordering, which is empty for most fields.
If you want to order by the title, you can simply choose the order by title ascending/descending option: https://i.imgur.com/clN5x0L.png
It is going to work, even if you have a custom field as the result titles.
If you also want to have the auto populated results ordered alphabetically, just use this configuration: https://i.imgur.com/lT65X5H.png
That should do the trick.