Hello ram doig,
Since you mentioned that the issue was started occurs after upgrade, so the issue is related to the VM extension telemetry or agent compatibility after the upgrade. Please check and confirm the following the insights from your end: Try to verify that the Azure Monitor Agent or Log Analytics Agent is running correctly on the upgraded VM. Because of upgrade, sometimes can cause the extension to malfunction.
Confirm the extension needs to be reinstalled or upgraded:
az vm extension list --resource-group <rg> --vm-name <vm-name> az vm extension show --name AzureMonitorWindowsAgent --resource-group <rg> --vm-name <vm-name> ``` if not reporting correctly
az vm extension set --resource-group <rg> --vm-name <vm-name> --name AzureMonitorWindowsAgent --publisher Microsoft.Azure.Monitor --version <latest-version>
Note: To make sure the above work as expected, you need to execute az login as mentioned above.
Hope this helps!
Please let us know if it was helpful, and feel free to reach out if you have any further queries.