Hi , Welcome to MS Q&A
I think given metrics available for the Microsoft.Web/serverfarms resource type which includes both Linux and windows plan , please check below Image where we can see the metric for both
So , I think it could be some intermittent data issue from your end that is not reflecting for windows
Check this doc for more ref https://learn.microsoft.com/en-us/azure/azure-monitor/reference/supported-metrics/microsoft-web-serverfarms-metrics
Linux Plan
Windows Plan
if you have questions , please let me know
Kindly accept answer if it helps
Thanks
Deepanshu