Hello Zeus G
Welcome to Microsoft Q&A Platform, thanks for posting your query here.
Thanks for sharing the link of the document and the details of VM OS and version.
This could be an issue with Azure Portal refresh. I would suggest you to try and restart the VM and see if that helps.
Also, you can try to check the status of the extension by running below command:
az vm extension list --resource-group <resource-group-name> --vm-name <vm-name> --show-details --query "[].{Name:name, ProvisioningState:provisioningState, Status:instanceView.statuses[0].displayStatus}" --output table
This will show you the status of all extensions installed on the VM. Look for the extension you're trying to install and check its provisioning state and status. If the provisioning state is "Failed" or "Canceled", there may be an issue with the extension installation.
Hope this helps.