Retirement tax questions

There is no lower case letter associated with box 12.  From a dropdown, I selected S - Contributions to 408(p) SIMPLE plan, as listed on my W-2. I'm getting a message that says: Check this entry - Form W-2: Box 12 code S --Should not be greater than the value in box 12 with code S for this W-2.  Box 12 code S: $x,xxx.xx

 

  The conflicting values are the exact same number.