Hello Thomas Herth, as you can read from the javadoc of JPA’s Predicate#getExpressions() method:

… Modifications to the list do not affect the query

I would suggest using a List<Predicate> instead and passing it to the CriteriaQuery#where(Predicate... restrictions) method.

Since the current behavior in Hibernate 6 is correct I will close this issue. Feel free to reach out if you need any additional information.