The async_publish_time.cpp code has a bug: the connection is closed before starting to publish timestamp messages

I found that the async_publish_time.cpp file cannot send timestamp messages correctly.
To find out why, I canceled the "send when dissconnected" connect option. It showed me that connection had been closed before publishment.
the code here is what I changed.
auto createOpts = mqtt::create_options_builder()
.send_while_disconnected(true, true)
.max_buffered_messages(MAX_BUFFERED_MESSAGES)
.delete_oldest_messages()
.finalize();

I change this part of code into this:

auto createOpts = mqtt::create_options_builder()
// .send_while_disconnected(true, true)
.max_buffered_messages(MAX_BUFFERED_MESSAGES)
.delete_oldest_messages()
.finalize();

Then I compile and execute this code, still can not receive message on server side.
This is part of code from "async_publish.cpp"

cout << "\nConnecting..." << endl;
mqtt::token_ptr conntok = client.connect(connOpts);
cout << "Waiting for the connection..." << endl;
conntok->wait();
cout << " ...OK" << endl;

and this is part of code from ”async_publish_time.cpp“：

cout << "Starting connection..." << endl;
cli.connect(connOpts);
auto top = mqtt::topic(cli, "data/time", QOS);
cout << "Publishing data..." << endl;

What's the difference? It is "->wait()"!!!! right!
After I corrected the ”async_publish_time.cpp“ into this:

cout << "Starting connection..." << endl;
cli.connect(connOpts)->wait();
auto top = mqtt::topic(cli, "data/time", QOS);
cout << "Publishing data..." << endl;

Then, I can publish data/time properly!

Start with async_publish_time.cpp and compare its connection sequence with async_publish.cpp, especially whether cli.connect(connOpts) is waited on before publishing. Confirm the example establishes the connection before creating the topic and sending timestamp messages; done means the server receives data/time messages reliably.