The table frame is not set correctly. Check the code or nib
The delegate returns the height of the header, and it is correct in the table, because there is no space between the edge of the table and the cell
use the setFramemethod for proper installation through code
0 . , 0,
- (CGFloat)tableView:(UITableView *)tableView
heightForHeaderInSection:(NSInteger)section
{
CGFloat height = 0.001;
return height;
}