Ilham Hanif Fathurrohim Greetings!
Can you confirm which devices are you referring to?
If you are referring to Azure IoT hub Devices, please see below.
- Are you able to see a device list, either within the portal or by using Azure CLI? az iot hub device-identity list
az iot hub device-identity list --hub-name <iothubname>
- Can you access the device logs of your IoT devices or can setup a debug device to test Iot Hub connectivity with the deployed configuration and SW version? See How to collect debug logs from your Azure IoT devices
Do let me know if you need further help.