Starting row of the range is too small - google-apps-script

Question

I have an issue that I cannot figure out. I wrote some code to take an item from a sheet called "Bag Label" and then look up its location in another sheet called "Inventory & Lots". and then to copy some of the cells to the right of that location.
It works well as long as the location is not row 80 or higher in sheet "Inventory & Lots". For the life of me, I cannot figure out why row 1 to 79 works but not 80+.
var ss=SpreadsheetApp.getActiveSpreadsheet();
var menuSheet=ss.getSheetByName("Bag Label");
var inventorySheet = ss.getSheetByName("Registered Lots");
var inventorySheetData = ss.getSheetByName("RegisteredLots - NO DEL");
var nextRow = inventorySheetData.getLastRow()+1;
var inventoryLots = ss.getSheetByName("Inventory & Lots");
var inventoryCalc = ss.getSheetByName("Inventory Calculation");
var inventoryCalcData = inventoryCalc.getRange(2,1,inventoryCalc.getLastRow()-1,4).getValues()
var inventoryData = inventoryLots.getRange(1,1,inventoryLots.getLastRow()-1,10).getValues()
var columnIndex = 0
var matchText = menuSheet.getRange("D2").getValue()
var kgNeed = menuSheet.getRange("AB2").getValue()
var index = inventoryData.findIndex(row => row[columnIndex] === matchText)
var rowNumber = index +1
var kg1 = inventoryLots.getRange(rowNumber,2).getValue();
var lot1 = inventoryLots.getRange(rowNumber,3).getValue();
var bb1 = inventoryLots.getRange(rowNumber,4).getValue();
var kg2 = inventoryLots.getRange(rowNumber,5).getValue();
var lot2 = inventoryLots.getRange(rowNumber,6).getValue();
var bb2 = inventoryLots.getRange(rowNumber,7).getValue();
var kg3 = inventoryLots.getRange(rowNumber,8).getValue();
var lot3 = inventoryLots.getRange(rowNumber,9).getValue();
var bb3 = inventoryLots.getRange(rowNumber,10).getValue();

Answer 1

Use array methods such as Array.filter() to get data more easily. Try this pattern to get started:
const ss = SpreadsheetApp.getActive();
const matchText = ss.getRange('Bag Label!D2').getValue();
const inventoryLots = ss.getSheetByName('Inventory & Lots');
const matchingData = inventoryLots.getDataRange().getValues()
.filter(row => row[0] === matchText);