Nice to hear that the explanation was detailed enough for you. Thanks for the quick reply!

I guess my understanding of what's happening beneath is not good enough to understand why this fails. I thought setting up the QueryBuilder in the following way:

fullTextSession.getSearchFactory().buildQueryBuilder().forEntity(ReportAccessArea.class).get();

made sure it would only look for ReportAccessArea related classes (belongs to index named ReportAccessArea) and not look into UserAccessAreaId (belongs to index named UserAccessArea), since they belong to two different indexes. When I perform a search using Luke I do not see any problem, and that was one of the things that made me think there might be something wrong within Hibernate Search.