What is the correct way to add/update a row in another table

[ali-hussain]

I need to define actions that add another row to another table but on updates I don't want to overwrite any existing data. My use case is I am collecting some telemetry for edits made by a user. I created a grouped action with the first action "Add a new row to another table" followed by an action that increments a count in that row by filtering the row I just added. Then I perform an increment action. When I first tried this, I noticed that Adding to the same row does not affect the values I did not touch. But after I migrated my target table to another spreadsheet the behavior changed. I saw the Add action started clearing out my counter. After trying to find any configuration differences I gave up. And just simplified to one action, that figures out if there is an existing value and incrementing accordingly when performing the Add.

But I did this in only one place. And wanted to understand what the correct behavior is. Is there an option I selected somewhere that changes the behavior of "Add another row to a table" or it was a timing fluke that it was ever working. Appreciate any help in this regard.

Edit: Added details and screenshots here: https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/What-is-the-correct-way-to-add-update-a-row-in-...