SEP Client 12.1.6 MP7 ost connection to SEPM 14 MP1

I have a SEPM 14 Servers running on Windows Server 2008 R2 Boxes, and SEP Clients 12.1.6 MP7 running on Windows XP，all clients use https  has connected to SEPM 14 Server normally.

After upgrade my SEPM 14 Boxes to SEPM 14 MP1, the SEP Client 12.1.6 MP7 on Windows XP lost connection to SEPM 14 MP1 Server , I used symdiag tools to diagnose , it say communication between Server and Client may not work , recieved messages error or data format error ....

I'm sure TLS option on internet control panel is enabled.

Any thoughts greatly appreciated.
Many Thanks