I think the hashCode must be computed on the result of disassemble( value, session ), otherwise each part of the compound natural id would require an implementation of equals/hashCode methods (not the case for the State class used in NaturalIdTest#testNaturalIdLoaderCached).

I have pushed my modifications to https://github.com/sdusart/hibernate-orm/tree/HHH-16218 but I’m really not sure of what I did…

./gradlew clean build finishes successfully...