Sorting order when searching for a string

Hello
I’m a little bit confused how the events are sorted when I capture a string to search for (and nothing else). I am using three different price categories. One of them is a featured category and the related events are listed first. So far so good. But then I have no clue how the sorting works as the price categories as well as the date of the events seem to be mixed up.
May I kindly ask you to take a look on my page? I will add it on a separate post.
Thanks and best regards
Jorge