(esp-idf) why cannot subscribe "$aws" topic

Question

i'm testing aws iot example code with esp32 and esp-idf

Using example below, https://github.com/espressif/esp-aws-iot/tree/master/examples/mqtt/tls_mutual_auth

It works well with normal topic(ex."esp/test/topic"). But It doesn't work with reserved topic(ex. "$aws/certificates/create/json/accepted")

example code show succeed to subscribe log, But i can't receive any message from reserved topic.

To provisioning i have to subscribe reserved topic below

• $aws/certificates/create/json/accepted
• $aws/certificates/create/json/rejected
• $aws/provisioning-templates/{template name}/provision/json/accepted
• $aws/provisioning-templates/{template name}/provision/json/rejected

But i can't get any message from these topic.

why it doesn't work?

thanks for your help