You can achieve this by creating a new column to store time data of when a task is last updated, setting up automations to properly update this column, and then modifying the list order to sort accordingly to display the last updated or newly added task at the top.
Here are the steps for this:
On the A_Task table, add a column named something like "Last Updated."
Then create an automation that will update "Last Updated" when "Notes" are modified. I did this with the Column Changes automation, selecting Overwrite as the action to update to =NOW() in the "Last Updated" column.
After publishing both automations, you can then see that when you either add a row or update the "Notes" column in a row, the "Last Updated" column updates.
For the last part to sort accordingly in the app by the last updated task, you will need to modify the list's data source in Builder. On the "All Tasks" screen, click on the list object, and in the data source, update the two "Order By" clauses.