Ok, I managed to solve it just by setting the style to dropdownlist, I don't need it to be dropdown anyway. But the problem stills exists.
answered on 28 Aug 2018, 12:48 PM
Thank you for writing.
I am not sure how you ended up with the formatted text in the editor of the RadDropDownList control. This editor actually extends the standard Microsoft text box and it cannot be used with HTML-like formatted text. You can try handling the VisualListItemFormatting event of the control and only format the item displayed in the list when it is open:
public partial class RadForm1 : Telerik.WinControls.UI.RadForm