Amazone S3 AWS Free Tier limits alert

Hello,

I'm in the process of tuning my electronic product to validate the choice of my client who wants to migrate his Azure IoT Hub Cloud to AWS IoT Core.

So I created a root account so that I could test connect and publish MQTT messages, (the device has no messages to receive from the Cloud). After some difficulties to connect my device, I managed to create up to two devices, and sent 4 or 5 messages of 1.54Kb each, (JSON file), which I checked the good reception by the AWS Cloud via MQTT Test Client.

What I don't understand is why I would have already exceeded the quota of 2000 POSTs or PUTs, etc... of the first year's free version?

My tests took place over 5 days maximum, and I only used the AWS Iot Core service, with the Create Object, Create Certificates with AWS and download of them, create Policy and attach to the certificates, and MQTT Test Service menus. It is true that I had trouble creating the right policy for the publication topic.

Is it very REST API consuming (PUT, COPY, POST, ...) ? How can I control the number of POSTs or PUTs sent and how are they issued? (The region chosen for my region is eu-west-3)

Thanks for your help, I need to understand in order to explain to my client. We did not have this kind of problem with AZURE.

Regards, Eric F