GROUP BY in a cross engine subquery generates bad results

select   lo_shipmode, c_region,  sum(lo_extendedprice), count(*) from     

   lineorder join customer on lo_custkey = c_custkey  

     where lo_orderdate between 

          (select d_start  from 

             (select d_yearmonthnum * 100 + 1 d_start  , count(*) from dateinfo 

                                where d_weekdayfl = 1 and d_year = 1998 

                                      group by 1 order by 2 desc limit 1) 

           alias1) 

           and 

           (select d_end  from 

              (select d_yearmonthnum * 100 + 31 d_end, count(*) from dateinfo 

                                where d_weekdayfl = 1 and d_year = 1998 group by 1 order by 2 desc limit 1)

           alias2) group by 1,2 order by 1,2;