Set-PnPTenantSite cannot add sharepoint admin without read access to site

[hacktron86]

Attempting the following with a SharePoint admin account that does not have any permissions on the site:

Connect-PnPOnline -Url "https://###-admin.sharepoint.com" -Interactive
Set-PnPTenantSite -Identity "https://###.sharepoint.com/sites/###" -Owners "[SharePoint admin account email]"

Returns the following error:

Set-PnPTenantSite: Attempted to perform an unauthorized operation.

Attempting the same thing with a SharePoint admin account that has ONLY read access (or more) to the site works.

The SharePoint admin account can add the account via the portal just fine - is there some step I'm missing to get this to work or is this a bug?

[hacktron86]

As a follow up I was able to solve this using Set-SPOUser. Still curious if this is a limitation of PnP PowerShell, a configuration or security policy or a bug.