Node Red Connection Problems

Hello aws - Forum!

I want to connect with Node-red via the mqtt node to the aws IoT. I use a Simatic IOT2040 which has actually a Arduino Uno in it with node-red. I have also a Temperatur Sensor connected to it, which i want to stream.
But i run out of ideas and cant get it work.
What have I tried yet:
For the aws Cloud.

• I followed step by step this giude:
  https://docs.aws.amazon.com/iot/latest/developerguide/iot-gs.html
  -registry my IOT
  -downloaded the certificate public, private, the certificate as well as the root CA.
  --create first txt file, write the rootCa in it, save it as pem file.
  -- via WinSCP on my Simatic /home/root/... folder
  -- activate it
  -- Attached it to my SImatic
  -create policy
  --Action iot:** Resource ARN **
  --Attach it to my certi

As well with configure a device Linux & node.js
-- with the download kit on the device
-- add permissions chmod +x start.sh
-- ./start.sh

installed this nodes:
https://flows.nodered.org/node/node-red-contrib-aws-iot-hub
Sending but not incoming at the cloud

In Node-Red:
First i tryied it with the default mqtt broker
Server: The Endpoint Http
Port:8883
Enable Secure SSL/TLS configuartion:
-- Certificate: on my Simatic /home/root/... folder the Certificate file ending .pem
--Private key:on my Simatic /home/root/... folder the Certificate file ending xxxprivate.key
-- CA Certificate; on my Simatic /home/root/... folder the 'manual' with txt file created CA root file.

Notice ; No Errors --> Startet "Connecting" but never is "Connected"

For testing i jist typed "payload" in the topic in the Cloud as well in the nodes and ot should give me to the sensor values.

So, what am I missing?

Kindly regards!

RoundTriangle