correlated subquery with covered index will not return results

create primary index on default;

create index ix1 on default(x);

insert into default values("kk02", {"x":100, "y":101, "z":102});

select d.x,d.y from default d where x IN (select raw d.x from default b use keys["kk02"]);

-- above query is not covered and return right results

select d.x from default d where x IN (select raw d.x from default b use keys["kk02"]);

-- above parent query is covered with index ix1 and will return no results.

............                       

    "~children": [

                                {

                                    "#operator": "Filter",

                                    "condition": "(cover ((`d`.`x`)) in (select raw (`d`.`x`) from `default` as `b` use keys [\"kk02\"]))"

                                },

..........