Hi!
Thank you for all the details, it helps a lot.
To search only a single category, this documentation will help you out.
I also checked, and the reason why that specific value is selected is, that it has a double star “**” within it’s title, see the source here: https://i.imgur.com/qaPAAka.png
The plugin uses that syntax to choose the selected item. Is it possible by any chance to remove that from the original, or is it required there in the airports title?