Workaround for GroupHeaderTemplate:
Workaround for column:
UPDATE:
We have decided not to change the code of the RadDataGrid component in this regard. The root reason for this is the fact that the Skia APIs used to draw the text does not support automatic character fallback. To overcome this issue, people from Skia team have two suggestions. We have tested them out and none of them is applicable for the case of the DataGrid.
First approach slows down the performance of the component to a point where the DataGrid becomes unusable.
Second approach does not fix the problem in all cases.
Having this in mind the best approach for our customers in such cases is to use a TemplateCell with a Label inside it only for the column(s) where they expect symbols to occur. The Xamarin.Forms.Label supports automatic character fallback hence it should properly handle all cases.