device connectivity issue when using TLS
I try to send mqtt messages to my Azure IoT hub using port 8883 and TLSv1.2. I uploaded CA certficate (Digicert Global Root G2) in my device, and use SAS authentication for device (client authentication). My hub's monitoring section shows there are "used messages", but not "sent telemetry messages", or even "failed telemetry messages". It seems my device is not connecting to IoT hub properly. I wonder why.
When I use Azure-cli I can see my messages in my hub using Azure iot explorer. I am also able to send mqtt messages with TLsv1.2 from node-red in my laptop to the Azure iot hub.
I connected to the iot hub one months ago, but do not remember the setting at that time, and now I am stuck. I think I did things without sever certificates. Is there any special consideration when uploading the certificate to my device? (like encoding or anything else) I just imported .pem or .cer file I downloaded from Digicert website. Do I need to upload the certificate in Azure somewhere or declare I am using it?
I would appreciate it if anyone help me to solve the issue.
Is there any technical support service for azure customers?