Input field disappears when hitting enter after filtering to something non-existing

1. Add a multiselect control with a string field (or picklist) and let it have two values, "foo" and "bar" for example. 
2. Click "No selection made" and write something else in the filter box, i.e. "hello", and press enter.

The input box vanishes, and there is no way to select any value until the form has been reloaded.
