Chinese message can not show correctly with IP*works! V8.x client

chinese message can not show correctly with IP*works! V8.x client

Openfire 3.6.4
Spark 2.5.8
IP*works component for delphi v8.x

IPworks! client can communicate well with spark client in Openfire server when sending english message, but when spark send chinese message to IPworks! client or recieve chinese message from IP*works!, the message can not show correctly.

i think that it is message encode problem, but i do not know how to resolve, can someone help me, thanks