Query text in highlighted content web part uses KQL.
I don't think there is any way to enforce sorting within the Query text box.
Workaround:
- Go to site collection settings --> Search Schema
- Search for managed property which starts with RefinableString
- You should be able to get the list pre-created refinable managed properties like RefinableString00, RefinableString01 and so on.
- Select a managed property which is not mapped already, and map it to your targeted crawled properties (Title and ows_ListTitle).
- Use this managed property in your sorting.
Setup

Output:

Note:
After mapping crawled properties, you may not be able to use the Refinable managed property in highlighted content web part settings.
So either you have to wait for some time till site gets crawled or you can re-index your site.
Re-indexing site:
- Go to site settings
- Select "Search and Offline Availability"
- Click "Reindex site" and wait for some time