I can't get the vertical divider to show up - it appears to have no styling so is invisible.
PowerShell Universal 2026.2.5 (32409143550)
It's also not shown in the showcase:
753e68df-252d-4592-913a-7b931bf8d491.png
I can get it to appear (but not as a proper vertical line), by doing a style override like:
New-UDDivider -Orientation 'vertical' -Sx @{
border = '10px solid Red'
}