Header view not showing at Section 0 - swift

Question

I add custom tableView header. My section count is 2 and the header is not displaying at section 0. But showing properly at section 1.
func numberOfSections(in tableView: UITableView) -> Int {
return arrRouteDetials.count
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
if section == 0 {
headerRadioBtn.tag = section
headerRadioBtn.addTarget(self, action:#selector(RdAction(_sender: )), for: .touchUpInside)
return viewTblHeader
}else{
headerRadioBtn.tag = section
headerRadioBtn.addTarget(self, action:#selector(RdAction(_sender: )), for: .touchUpInside)
return viewTblHeader
}
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return arrOfSectionRowValue[section].count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "BranchUnloadingcell", for: indexPath) as! BranchUnloadingcell
cell.lblSerialNo.text = "\(indexPath.row + 1)"
cell.val = arrOfSectionRowValue[indexPath.section][indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
self.viewWillLayoutSubviews()
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 74
}