The cpp example hello_world, loss data

[h2cw2l]

fastdds version:3.4.0
I use the cpp example hello_world，I added a data to the idl.
@extensibility(APPENDABLE) struct HelloWorld { unsigned long index; string message; octet data[602112]; };
When run the example, there is always some data loss in the begin.
publisher:

subscriber:

I run publisher and subscriber in the same host.