AWS IoT topic subscribe callback never called
I am using AWS IoT and I am trying to subscribe to a topic using the package "simple" or the code in the AWS example on pycom website. The subscription seems to be successful and I expect my callback to be called when i publish messages to the topic I subscribed to. I am, of course, able to publish without issues but cannot subscribe.
I am testing everything using AWS tools. The integrated web-based client and observing events about "things". When i subscribe, I can see trace of this subscription and the fact it was successful. When i publish, I see my messages in the relative topics.
Although I am using "simple" right now, I have tried with both simple and the guide in the pycom documentation. I suspect at this point a misconfiguration from the side of AWS. This issue seems to be silent though. Subscription and publishing is successful! Receiving messages is not.
I was wondering if somebody has some advice or some experience to share about this issue.
Just to recap:
Certificates are correct
Endpoint is correct
Connection is successful
Publishing is successful
Policy is correct (can subscribe to anything)
Subscription is successful
-> Receiving messages is not successful <-
any help is appreciated!
The problem has been solved by adding a receive policy to the group the thing belongs to.