search pops up an error message if you don't type fast enough

On a website I have two exposed filters combined with a search option (key filter). If you type hesitatingly, the search will interrupt you and tell you to supply a keyword with three or more letters. If you then continue to type, the search will interrupt you once more almost immediately with no results because the search startet with an incomplete word.

That's somewhat irritating for users and I haven't found a way to configure the behaviour of the search field. Is there such a possibility?
And is there a possibility to tell the filters to display "all" by default?

Thanks a lot.

Patrick