Possible bug in Data Grid

Product: PowerShell Universal
Version: 4.2.4

I am working on moving to Data Grid from tables and getting the error message ‘Cannot index into null array’, so I copied this code to troubleshoot from the documentation site https://docs.powershelluniversal.com/userinterfaces/components/data-display/data-grid#example-static-data
This happens when the column sort is clicked 3 times, so works, works, does not work on third click on sorting of any column.

When I look at $EventData in the LoadRows script block block of New-UDDataGrid I see the sort property is empty on the third click causing the error in the code.

Is this a bug or by design?