Symptoms

The ListSearcher erroneously outputs features from the NOT_FOUND port when the expression to search for is set to "^1$|^9$|^10$".  

Cause

The ListSearcher cannot handle the regular expression "^1$|^9$|^10$".   

Resolution

This will be fixed through problem report PR #36244.  As a workaround, explode the features with a ListExploder and use a StringSearcher (which does handle the expression).