Goggle Sheets - Add Row and sort - sorting

Question

Total beginner here so please dumb down your answers lol - How do I add a blank row to a specific row in google sheets that is being sorted without the row moving before I can edit it? I'm happy to change my system as needed.
Basically, I'm building an internal workflow program and have an auto-sort script for a list of jobs, when the jobs are completed the staff change row 1 from "A" to "Z" which pushes that row/job to the bottom of the sheet. However, the problem we have is when we add new work by inserting a row and start typing....the row moves before we can put data into it - it's a pain - what ideas does everyone have where I can improve this?
Thoughts / Ideas?
This is the sort script I have at the moment.
function onEdit(event){
var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Large")
var editedCell = sheet.getActiveCell();
var columnToSortBy = 1;
var tableRange = "A9:M100";
if(editedCell.getColumn() == columnToSortBy){
var range = sheet.getRange(tableRange);
range.sort( { column : columnToSortBy } );
}
}

Answer 1

I could find two possible solutions:
1- Use the cell's oldValue, it's value is undefined whenever you add a value to the cell for the first time. Using this solution will sort the table if you change the value a second time:
function onEdit(event){
var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Large")
var editedCell = sheet.getActiveCell();
var columnToSortBy = 1;
var tableRange = "A9:M100";
if(editedCell.getColumn() == columnToSortBy && event.oldValue != undefined){
var range = sheet.getRange(tableRange);
range.sort( { column : columnToSortBy } );
}
}
2- Sort only if the the cell is changed to Z, update the condition to:
if(editedCell.getColumn() == columnToSortBy && event.oldValue === "Z"){
Reference:
Event Objects