No scroll buttons on New-UDTabs [v4.0.7]

Product: PowerShell Universal
Version: 4.0.7

I’m trying to get -scrollbuttons to work on New-UDTabs but cant see that it’s making any difference.

Here’s my example code:

New-UDTabs -Tabs {
    New-UDTab -Text 'Test1' -Icon (New-UDIcon -Icon house) -Content {
    }
    New-UDTab -Text 'Test2' -Icon (New-UDIcon -Icon house) -Content {
    }
    New-UDTab -Text 'Test3' -Icon (New-UDIcon -Icon house) -Content {
    }
    New-UDTab -Text 'Test4' -Icon (New-UDIcon -Icon house) -Content {
    }
    New-UDTab -Text 'Test5' -Icon (New-UDIcon -Icon house) -Content {
    }
    New-UDTab -Text 'Test6' -Content {
    }
} -ScrollButtons on

When I minimise the width of the browser it cuts off items in my menu and there are no scroll buttons from what I can see.