When the query connects two or more tables, the query results are inconsistent whether the order by field is in the select field or not

select CUSTOMER.C_PHONE
-- ,LO_PARTKEY
from SSB.CUSTOMER left join SSB.LINEORDER on CUSTOMER.C_CUSTKEY=LINEORDER.LO_CUSTKEY
order by LINEORDER.LO_PARTKEY NULLS LAST
LIMIT 500

KapProjectRel(C_PHONE=[$6], ctx=[])
  KapLimitRel(ctx=[], fetch=[500])
    KapSortRel(sort0=[$12], dir0=[ASC], ctx=[])
      KapJoinRel(condition=[=($0, $11)], joinType=[left], ctx=[])
        KapTableScan(table=[[SSB, CUSTOMER]], ctx=[1@NDataflow [test]], fields=[[0, 1, 2, 3, 4, 5, 6, 7, 8]])
        KapTableScan(table=[[SSB, LINEORDER]], ctx=[2@NDataflow [test1]], fields=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]])

select CUSTOMER.C_PHONE
,LO_PARTKEY
from SSB.CUSTOMER left join SSB.LINEORDER on CUSTOMER.C_CUSTKEY=LINEORDER.LO_CUSTKEY
order by LINEORDER.LO_PARTKEY NULLS LAST
LIMIT 500

KapLimitRel(ctx=[], fetch=[500])
  KapSortRel(sort0=[$1], dir0=[ASC], ctx=[])
    KapProjectRel(C_PHONE=[$6], LO_PARTKEY=[$12], ctx=[])
      KapJoinRel(condition=[=($0, $11)], joinType=[left], ctx=[])
        KapTableScan(table=[[SSB, CUSTOMER]], ctx=[1@NDataflow [test]], fields=[[0, 1, 2, 3, 4, 5, 6, 7, 8]])
        KapTableScan(table=[[SSB, LINEORDER]], ctx=[2@NDataflow [test1]], fields=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]])