Hi @Satyam Chauhan Thank you for posting the question here.
When you perform
sudo iotedge check on an IoT Edge device, the IoT Edge check tool uses a container to run its diagnostics. The container image,
mcr.microsoft.com/azureiotedge-diagnostics:latest, is available through the Microsoft Container Registry. Since you are running a check on a device without direct access to the internet, your devices will need access to the container image. You can either create a local copy of the container on your IoT Edge device or if you have a parent device, you can use the below command on downstream devices to route the image pull through the parent devices.
sudo iotedge check --diagnostics-image-name <parent_device_fqdn_or_ip>:<port_for_api_proxy_module>/azureiotedge-diagnostics:1.2
Since the connectivity checks also rely on this container image, I would suggest to resolve this and perform the check to see the correct results.
Please refer the following section Run the check command for more details on this.