I tried AutoFit="true" TextAlign="TextAlign.Left" and messing with the widths. I'm having difficulty getting the headers to line up with the columns.
Your requirement can be achieved by setting HeaderTextAlignment as a start on manually generated columns. For more details please refer to the below UG link.
UG link : https://help.syncfusion.com/xamarin/datagrid/column-types#headertextalignment
Regards, Karthik Raja