TiDB cannot push down broadcast join which has aggregations in one of data side

[flowbehappy]

set @@session.tidb_allow_batch_cop=1; # 合并对 TiFlash 的数据请求
set @@session.tidb_opt_broadcast_join=1; # 开启 broadcast join 优化，
explain analyze
select
       max(`name`) as name,
       value,
       max(hopIpValue) as hopIpValue,
       max(hop_type) as hopType,
       case when max(`group1`)='' then '未知' else max(`group1`) end as `group`,
#        arrayStringConcat(groupUniqArray(active_state_unit),',') as protocol,
       case when (max(t3.`group1`)='' and value not like '%_*' and value !='*') then 0 else 1 end as status,
       max(`deviceType`) as deviceType,
       min(hop) as minHop,
       max(endTime) as endTime
from (
         SELECT /*+ broadcast_join(t1, t2),  broadcast_join_local(t1) */
                t1.hop_ip as `name`,
                t1.hop as `hop`,
                hop_ip_int as `hopIpValue`,
                t1.hop_ip as value,
                case when t1.hop_ip=t1.ip then 1 else 0 end as hop_type,
                t1.active_state_unit as active_state_unit,
                t1.hop_ip_bizgroup as `group1`,
                t1.device_type as `deviceType`,
                t1.end_time as endTime
         from vnap_data.active_trace_topology_gz as t1
                   INNER JOIN (
             SELECT task_id, max(hop) as hop
             from vnap_data.active_trace_topology_gz
             WHERE end_time >1591080948
             group by task_id
             ) as t2
                  on t1.task_id = t2.task_id
         WHERE end_time >1591080948  and t1.hop<=30 and t1.hop >0 and (t1.hop_ip!=t1.ip) and t1.hop_ip!=t1.src_ip
) as t3
group by value
order by hopIpValue asc;

explain.xlsx