Some PnP Cmdlets stopped working?

[MarkFrenchAN]

I've recently made use of some PnP Cmdlets to successfully get and set site level permissions in SharePoint Online, but they don't seem to be working any more, has something changed?

The couple of examples I have are: Grant-PnPAzureADAppSitePermission and Get-PnPAzureADAppSitePermission but there may well be others that we haven't tried so far. These both fail with an error message along the lines of:

Get-PnPAzureADAppSitePermission : Operation not supported

I don't believe anything has changed in the way I'm attempting to use the commands, the initial connection using Connect-PnPOnline appears to still work OK and I'm able to run other commands successfully after that, such as Get-PnPAzureADAppPermission, it's just these couple specifically that I've seen these "Operation not supported" type responses for at the moment.