There is an unsaved comment in progress. You will lose your changes if you continue. Are you sure you want to reopen the work item?
DataGrid has quite few problems when it comes to design. Your new fix worked for the scrollbar, but it changed headers so the text height doesnt fit anymore (Screenshot).
Another error is with the DataGrid transparency, nothing seems to get this done.
Another bug is when I want whole row to be selected, clicking on column still makes a square border around it.
When I have time I will look into those bugs myself too.