The timestamp that never advanced
A JSON column was updated in place without touching updated_at, so every relative timestamp in the product was really a creation date.
It said it worked
Green, 200, saved, “already handled” — and wrong. No error anywhere to go on.
Found while reverting a test value: after saving Platform Settings through the UI the row's settings_json had visibly changed and updated_at hadn't. Every relative timestamp in the product was quietly a creation date wearing a modification date's label. Nothing crashes and the number shown is a real number, which is why it lasted.