Thanks for reaching Q&A
Just checked from my end and looks fine working.
Could you please answer the questions below?
1- Which AKS version are you using? Is a supported version like below? If you not using a supported version, please upgrade so you can have the latest container image metrics.
2- If you have a supported, please try to delete the metrics pods "kubectl delete pod -n kube-system metrics-server-XXXXXXX --force". Check after the Azure portal.
3- If still persists please disable and enable again the addon monitoring.
az aks disable-addons -a monitoring -n <cluster-name> -g <cluster-resource-group-name>
az aks enable-addons -a monitoring -n <cluster-name> -g <cluster-resource-group-name>
4- If not resolve with the steps above please raise a ticket to Microsoft support.
Hope this helps. Please "Accept as Answer" if it helped, so that it can help others in the community looking for help on similar topics.