List Append order is wrong

"INSERT INTO collection_type(key,normal_column,list_column) VALUES ('k','value',[ '#293847','#323442' ]);"

"UPDATE collection_type SET list_column=list_column+'#611987' WHERE key='k`;"

Using 2.1.7.1 java driver to run Update query, the output is: '#611987', '#293847','#323442'

Using DevCenter 1.3.1 to execute Update query, result is in correct order: '#293847','#323442', '#611987'

The error happened in 3 node cluster. In local, one node is working properly.
(all Cassandra 2.1.13. )

Is it related to internal message processing?