The @Convert annotation is ignored in specific circumstances when performing HQL (or Criteria) queries.
Specifically, the converter is ignored when querying for negative values, or updating to negative values.
According to our debugging, org.hibernate.hql.internal.ast.tree.BinaryLogicOperatorNode#initialize would expect an ExpectedTypeAwareNode (e.g. a LiteralNode) as right-hand-side (or left-hand-side), but is getting an UnaryOperatorNode in these cases.
See the attached test-case project.
Spring-Boot 2.1, Java 8, Windows 10, H2DB