Using sprintf and nextion display

Other Hardware Displays
7

I just tried (Set Serial2.begin(9600);
Serial2.print("n31.font=1");
NexEnd();
Serial2.print("n31.pco=2016");
NexEnd();

that changes nothing on the Nextion
but
mySerial.print("n31.font=1");
NexEnd();
mySerial.print("n31.pco=2016");
NexEnd();
Works just fine