TADVStringgrid header columns will not multilined

I use this class procedure to configure the stringgrid:

class procedure TBasisBlader.SetupBladerGrid(aGrid: TadvStringGrid; aHeaders : string; aColWidth : array of smallint);
begin
  LastColumnWidth := 0;
  aGrid.FixedCols := 0;
  aGrid.DefaultRowHeight := 25;
  aGrid.RowCount := 2;
  var MyHeaders : TArray<string> := aHeaders.Split([',']);
  for var regel in MyHeaders do
     aGrid.Columnheaders.Add(regel);
end;

Calling the procedure with this piece of code:

advstringgrid1.WordWrap := true;
TBasisBlader.setupbladergrid(advstringgrid1,'Aantal'#13#10'gebruikers vanaf,Licentieprijs,Periode, Prijscorrectie',[150,100,80]);

The first column shows the word before the linebreak, but the rest is not visible because the headercolumn is not multilined. Is it possible to do it?

RowHeight of 25 seems small for showing 2 lines of text.
Did you try to increase the rowheight?