Reset value in data grid selection

I seem to be having an issue using Sync-UDElement with a dataGrid in that it is not resetting the selected value each time.

Set-UDElement -id "tbNonEmployee" -Properties @{ selection = @() }
Sync-UDElement -Id "tbNonEmployee"

What ends up happening is that whatever was selected before the Sync-UDelement call remains in the Selected array. Is there a way to reset the selection attribute properly?