When image is being inserted to the ActionButton in RadSplitButton the ArrowButton might get overlaped if the text of the ActionButton is very long.

Workaround is to subtract the width of the image from the width of the text manually.

int actionButtonWidth = radSplitButton1.DropDownButtonElement.ActionButton.Size.Width;
int imageWidth = 40; // Sample rate should be equal to the width of the image in pixels

int desiredTextWidth = actionButtonWidth - imageWidth;

radSplitButton1.DropDownButtonElement.ActionButton.TextElement.MaxSize = new Size(desiredTextWidth, 0);

radSplitButton1.DropDownButtonElement.ActionButton.TextWrap = true;