The query (cvtype='problem') and (problem_description match '*Y*') does not give any output in IBM Rational Change.
Change query does not take more than 64 characters in to consideration while running the query.
This issue has been identified as a product defect under APAR PM11266.
The match operator in Rational Synergy only searches the first 64 characters.
The same limitation applies to Rational Change, as it shares the underlying query language and database.
Diagnosing the problem
If the letter 'Y' is the 65th character in the Problem Synopsis filed of a CR, then the above query will not find any matches.
Resolving the problem
There is currently no workaround available.