Check-offs rarely vanish for good. Usually one of these explains it.
- You tapped the habit again. Tapping a done habit undoes today's check-off. Tap it once more to check it off again.
- Changes haven't synced yet. Check-offs made offline or on another phone show up once both phones are online and the app is opened. See My habits aren't syncing.
- You logged out. Logging out clears the phone, but your habits stay in your account. Log back in with the same method to get them back.
- You're in a different account. Logging in with Apple on one phone and email on another can mean two separate accounts.
- You chose "My account" on the conflict screen. That replaces this phone's habits with your account's. See The data conflict screen.
- The habit is archived. It's hidden from Today but its history is kept. Find it under Profile › Archive.
Only today can be checked off, so a missing past day can't be added back by hand. See Can I check off a past day?
If none of these fit, contact us with the habit name and the dates that went missing.