Truncation does not work with word index unanchored phrases; that is, words combined using quotation marks. It works either with simple word searches or with anchored phrases e.g. ti=musical theat*.
Truncation of words in a word index cannot be done when combining the words in an unanchored word phrase
Learn more about anchored and unanchored searching in WorldCat Discovery
When I search for a title with special characters I get zero results