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).