Why isn't the dropdown hidden when selected in bootstrap-select (selectpicker)?

Question

JavaScript

I'm using bootstrap-select (selectpicker) to style the select.
Everything works, styling is tightened. But for some reason, the dropdown list is not hidden when any of the items is selected. Initially, everything is OK, the list appears as it should when you click on the input itself. But then it doesn't turn back. The item itself is displayed in the input field, but the list remains hanging.