This is likely due to the VMs being scale set VMs.
The 'Disk State' is not available for scale set VMs because they are collected via a different API than regular VMs which does not include power state in the response and therefore doesn't appear in the platform.
When hovering over the 'Disk State' column, is it mentioned that Disk State is not supported.
Also note that when the platform can't collect 'Disk State', it also can't identify disk cost by attached status. Instead, these costs are categorized as 'Other':