When using filters in Search, the Apply button in the filter setup do not work unless there is a match in the "pre-fetched" data

Thanks for the detailed feedback and for describing the filter behavior you’re encountering. I’ve shared this with the Search team so they can take a closer look and follow up.

It does sound like the behavior is tied to the sample set (e.g. the first X instances returned by the list API), but I want to make sure we understand your expectations correctly,  prompting to the user “ more matches could be there, press Enter/Return to proceed”, correct?

The problem is the design of the filter config.

If I want to create a filter for a property using “Is equal to”, it makes sense that I select the items/phrases I want to filter on from a list, like I would do if I eg select a specific system nr to filter on. The Apply button is only activated if I check at least one alternative. This works well as long as the items I want to select is in the “pre-loaded list”.

The problem arises for the other filter settings, like “Starts with”, or “Doesn’t start with”. 
In this situation I want to filter on a phrase that is (or isn’t) a subset of a text string. This means that even though there might be some examples in the list that starts with the phrase I want to filter on, I do not want to select them because then I would filter on that entire string and not the phrase I entered that may match many (but different) strings.

The only way to write my “free-text” and add that as the filter string, is by pressing Return after I have typed in the text (while the text field is activated). The Apply button is apparently always operating under the logic that the user needs to select an item from the list, which doesn’t make sense in this situation. I am able to accomplish what I want, which is to create a filter phrase that doesn’t necessarily exist in the list, but the way to do it is not logical due to the Apply button not understanding I’m in a setting where I do not necessarily select from a list.

In short, the Apply button is not able to understand it should behave differently depending on the type of filter criterion the user selects (like “Is equals to” or “Starts with”)