Reading Excel using ClosedXML - Range is wrong - out-of-memory

Question

I'm using ClosedXML to read in what appears to be a simple Excel file. But my program gets an out of memory exception.
Using some standard code to read in Excel sheet to a datatable:
public static void GetDataFromExcel(ref DataTable dt, string path, dynamic worksheet, bool header) //+EAG 6/8/2022
{
//Save the uploaded Excel file.
//DataTable dt = new DataTable();
//Open the Excel file using ClosedXML.
using (XLWorkbook workBook = new XLWorkbook(path))
{
//Read the first Sheet from Excel file.
IXLWorksheet workSheet = workBook.Worksheet(worksheet);
//Create a new DataTable.
// Does the first row contain headers ?
bool firstRow = false;
if (header) firstRow = true;
//Loop through the Worksheet rows.
foreach (IXLRow row in workSheet.Rows())
{
//Use the first row to add columns to DataTable.
if (firstRow)
{
foreach (IXLCell cell in row.Cells())
{
if (!string.IsNullOrEmpty(cell.Value.ToString()))
{
dt.Columns.Add(cell.Value.ToString());
}
else
{
break;
}
}
firstRow = false;
}
else
{
//Add rows to DataTable.
dt.Rows.Add();
int i = 0;
foreach (IXLCell cell in row.Cells())
{
string val = string.Empty;
try
{
val = cell.Value.ToString();
}
catch { }
dt.Rows[dt.Rows.Count - 1][i] = val;
i++;
}
}
}
}
}
The actual spreadsheet has only columns A -> O being used and there are only 130 rows in it. I've used this method in the same program to read in 3 other much larger spreadsheets without issue.
Not sure how to track down a solution to this. Any ideas ?