IndexOutOfRangeException on a multidimensional array despite using GetLength check

I am using the following code to read values ​​from an Excel spreadsheet:

// Start with passed
int lastPassRow = sheets[passedVehicles].GetLength(0);

for (int i = 1; i < lastPassRow; i++)
{
   // Exception here
   if(DateTime.TryParse(sheets[passedVehicles][i, 0].ToString(), out result))
   {
      passedDates.Add((DateTime)sheets[passedVehicles][i, 0]);
   }
}

      

        
        
        
      

    

The type sheets[passedVehicles]

is a multidimensional array Object[,]

and the for loop above gives me an exception IndexOutOfRange

at i = 1, even though I am checking the number of lines.

I added some logs for the spreadsheet in question and confirmed:

• i = 1 - iteration that fails
• The value lastPassRow
  
  is 4
• The value is sheets[passedVehicles].GetLength(1)
  
  also 4.

All values ​​turn out to be in range for me. Is there something else that might cause this exception?

Note. I am starting with i = 1 because row 0 is the header in the spreadsheet and does not contain the data I am trying to read.