B4J Question [XLUtils] Does not detect columns with letter Z

Private Sub AddressCells
    Log(xl.AddressZeroToString(50, 0))
    Log(xl.AddressZeroToString(51, 0))
    Log(xl.AddressZeroToString(52, 0))
End Sub

'Return
'AY1
'B@1 <-- ??
'BA1