Inheritance not returning correct result

[Dtenwolde]

Inheritance doesn't always seem to reproduce the right result. The below statement should return a single row with a person living in a city, but the result is empty.

To reproduce:

require duckpgq

import database 'duckdb-pgq/data/SNB1-projected|';

-CREATE PROPERTY GRAPH snb_projected
VERTEX TABLES (
    Forum LABEL Forum,
    Message LABEL Message IN Subcategory(Comment, Post),
    Organisation LABEL Organisation IN Subcategory(University, Company),
    Person LABEL Person,
    Place LABEL Place IN Subcategory(Continent, Country, City),
    Tag LABEL Tag,
    TagClass LABEL TagClass
    )
EDGE TABLES (
    Comment_hasCreator_Person   SOURCE KEY (CommentId) REFERENCES Message (id)
                            DESTINATION KEY (PersonId) REFERENCES Person (id)
                            LABEL Comment_hasCreator,
    Comment_hasTag_Tag      SOURCE KEY (CommentId) REFERENCES Message (id)
                            DESTINATION KEY (TagId) REFERENCES Tag (id)
                            LABEL Comment_hasTag,
    Comment_isLocatedIn_Country     SOURCE KEY (CommentId) REFERENCES Message (id)
                            DESTINATION KEY (CountryId) REFERENCES Tag (id)
                            LABEL Comment_isLocatedIn,
    Comment_replyOf_Comment SOURCE KEY (Comment1Id) REFERENCES Message (id)
                            DESTINATION KEY (Comment2Id) REFERENCES Message (id)
                            LABEL replyOf_Comment,
    Comment_replyOf_Post    SOURCE KEY (CommentId) REFERENCES Message (id)
                            DESTINATION KEY (PostId) REFERENCES Message (id)
                            LABEL replyOf_Post,
    Forum_containerOf_Post  SOURCE KEY (ForumId) REFERENCES Forum (id)
                            DESTINATION KEY (PostId) REFERENCES Message (id)
                            LABEL containerOf,
    Forum_hasMember_Person  SOURCE KEY (ForumId) REFERENCES Forum (id)
                            DESTINATION KEY (PersonId) REFERENCES Person (id)
                            LABEL hasMember,
    Forum_hasModerator_Person   SOURCE KEY (ForumId) REFERENCES Forum (id)
                            DESTINATION KEY (PersonId) REFERENCES Person (id)
                            LABEL hasModerator,
    Forum_hasTag_Tag        SOURCE KEY (ForumId) REFERENCES Forum (id)
                            DESTINATION KEY (TagId) REFERENCES Tag (id)
                            LABEL Forum_hasTag,
    Organisation_isLocatedIn_Place  SOURCE KEY (OrganisationId) REFERENCES Organisation (id)
                            DESTINATION KEY (PlaceId) REFERENCES Place (id)
                            LABEL Organisation_isLocatedIn,
    Person_hasInterest_Tag  SOURCE KEY (PersonId) REFERENCES Person (id)
                            DESTINATION KEY (interestId) REFERENCES Tag (id)
                            LABEL hasInterest,
    Person_isLocatedIn_City     SOURCE KEY (PersonId) REFERENCES Person (id)
                            DESTINATION KEY (CityId) REFERENCES Place (id)
                            LABEL Person_isLocatedIn,
    Person_knows_person     SOURCE KEY (Person1Id) REFERENCES Person (id)
                            DESTINATION KEY (Person2Id) REFERENCES Person (id)
                            LABEL Knows,
    Person_likes_Comment    SOURCE KEY (PersonId) REFERENCES Person (id)
                            DESTINATION KEY (CommentId) REFERENCES Message (id)
                            LABEL likes_Comment,
    Person_likes_Post       SOURCE KEY (PersonId) REFERENCES Person (id)
                            DESTINATION KEY (PostId) REFERENCES Message (id)
                            LABEL likes_Post,
    Person_studyAt_University   SOURCE KEY (PersonId) REFERENCES Person (id)
                            DESTINATION KEY (UniversityId) REFERENCES Organisation (id)
                            LABEL studyAt,
    Person_workAt_Company   SOURCE KEY (PersonId) REFERENCES Person (id)
                            DESTINATION KEY (CompanyId) REFERENCES Organisation (id)
                            LABEL workAt,
    Place_isPartOf_Place    SOURCE KEY (Place1Id) REFERENCES Place (id)
                            DESTINATION KEY (Place2Id) REFERENCES Place (id)
                            LABEL isPartOf,
    Post_hasCreator_Person  SOURCE KEY (PostId) REFERENCES Message (id)
                            DESTINATION KEY (PersonId) REFERENCES Person (id)
                            LABEL Post_hasCreator,
    Message_hasCreator_Person   SOURCE KEY (MessageId) REFERENCES Message (id)
                            DESTINATION KEY (PersonId) REFERENCES Person (id)
                            LABEL Message_hasCreator,
    Message_hasTag_Tag      SOURCE KEY (MessageId) REFERENCES Message (id)
                            DESTINATION KEY (TagId) REFERENCES Tag (id)
                            LABEL Message_hasTag,
    Message_isLocatedIn_Country SOURCE KEY (MessageId) REFERENCES Message (id)
                            DESTINATION KEY (CountryId) REFERENCES Place (id)
                            LABEL Message_isLocatedIn,
    Post_hasTag_Tag         SOURCE KEY (PostId) REFERENCES Message (id)
                            DESTINATION KEY (TagId) REFERENCES Tag (id)
                            LABEL Post_hasTag,
    Post_isLocatedIn_Country    SOURCE KEY (PostId) REFERENCES Message (id)
                            DESTINATION KEY (CountryId) REFERENCES Place (id)
                            LABEL Post_isLocatedIn,
    Tag_hasType_TagClass    SOURCE KEY (TagId) REFERENCES Tag (id)
                            DESTINATION KEY (TagClassId) REFERENCES TagClass (id)
                            LABEL hasType,
    TagClass_isSubClassOf_TagClass  SOURCE KEY (TagClass1Id) REFERENCES TagClass (id)
                            DESTINATION KEY (TagClass2Id) REFERENCES TagClass (id)
                            LABEL isSubClassOf
    );

# IS2
-FROM GRAPH_TABLE (snb_projected
     MATCH (a:person where a.id = 4026)-[i:Person_isLocatedIn]->(c:City)
     COLUMNS(a.firstName, a.lastName, a.birthday, a.locationIP, a.browserUsed, c.id, a.gender, a.creationDate)
     ) tmp;