Easy to reproduce.
Unzip attached. I've only included the project as the zipped solution with its lib was too big to upload.In function that's located in a RadForm
void DoSomething(Form form)
{
MessageBox.Show(form.FormBorderStyle.ToString());
MessageBox.Show(this.FormBorderStyle.ToString());
}
It returns "none" if form is a RadForm. The 2nd messagebox shows "sizeable" as this is a radform.
I wondered why it's doing this if a RadForm is a descendent.