New-SPOSiteGroup : The permission level is not a supported permission.

Hello, everybody.

I'v got a problem with performing the cmdlet 'New-SPOSiteGroup' on my SharePoint Online sites.

Trying to run
New-SPOSiteGroup -Site https://companyName.sharepoint.com -Group 'TEST' -PermissionLevels 'Design'

and it reports a error:

New-SPOSiteGroup : The permission level 'Design' is not a supported permission.

It does not work with any other permission level (Full Control, Contribute, whatever) either.

It does not work on any other sites 'inside'. Like https://companyName.sharepoint.com/sites/siteName

The account is a SharePoint admin and has all the required rights. I can create groups via a browser with no problem.

I also can successfully perform all the other cmdlets from Online PowerShell Module.

Any ideas would be great.

Thanks.