Items fail to delete if they include a regex special character

You forgot to escape the values string before using it in the regular expressions that remove a deleted item's values from the input in Drupal.autocomplete_deluxe.MultipleWidget.Item.prototype.remove.

This means that, if a term or other item includes a regex special character - for example, brackets/parenthesis, for example, in a taxonomy term like "United States of America (USA)", deleting it will remove the element from the page, but won't remove the invisible input element, because the regex that finds it is borked. So, if it is already saved to the database, it'll stubbornly refuse to delete on entity save, even though it will look like it has been deleted.

That function should look like this:

  Drupal.autocomplete_deluxe.MultipleWidget.Item.prototype.remove = function() {
    alert("REMOVE");
    this.element.remove();
    var values = this.widget.valueForm.val();
    var escapedValue = Drupal.autocomplete_deluxe.escapeRegex( this.item.value );    // new
    var regex = new RegExp('( )*""' + escapedValue + '""|' + escapedValue + '( )*', 'gi');   // editted
    console.log(this.widget.valueForm.val, this.widget.valueForm);
    this.widget.valueForm.val(values.replace(regex, ''));
    delete this.widget.items[this.value];
  };

In fact, there are several places where the string going into the regex isn't escaped - $.ui.autocomplete.prototype._renderItem is another one. Not sure if that one causes problems, looks like it might.

The 7.x-2.x branch is riddled with bugs. It should not be the recommended release. 7.x-1.x branch should be brought back until the 7.x-2.x branch is ready.