New-UDTextbox Date Type

Product: PowerShell Universal
Version: 4.2.1

The New-UDTextbox with a Type parameter set to date only shows mm/dd/yyyy for an assigned value but it appears a valid entry is there when entering and then exiting the field. The toast message indicates the value.

Am I missing something?

New-UDDashboard -Title "Test Dashboard" -Content {
    New-UDTextbox -Value '1/1/1970' -Type date -OnBlur {Show-UDToast $body}