Why won't the app blank my list if a sync comes back empty?
The app has built-in safety so a temporary cloud hiccup can never wipe your to-dos by mistake. If a sync comes back incomplete, or suddenly returns zero to-dos when you were holding a full list, the app refuses to apply it and keeps your last known-good list, retrying instead. A genuine "clear everything" only takes effect after it's confirmed on a second clean check. So a real deletion does sync through — it just has to be confirmed first.