When a night is missing, split, or credited to the wrong tracker, one of five rules usually explains it. Work through these checks in order.
011. Check when the sleep ended
Titan assigns a sleep session to the day it ends on, in your phone's local time. The session must end after midnight and no later than 12:00 PM. Sleep that ends after noon counts for no day. A lie-in until 12:30 PM, a daytime sleep after a night shift, and an afternoon nap all fall outside the window, so that day shows no sleep.
022. Check for a gap of more than 2 hours
Titan joins sleep samples into one session when each starts within 2 hours of the previous one ending. A longer gap splits the night in two. When two sessions end on the same morning, Titan keeps the one with more time asleep and drops the other. A 3-hour wake in the night leaves only the longer half in your score.
033. Check your Sleep Tracker and HealthKit Sources
Open Settings from the avatar on Today, then You > Settings. Go to Recovery & Sleep > Sleep Preferences > Sleep Tracker. Titan reads your chosen tracker first. The tracker only takes effect if an app or device whose name matches it has written sleep in the last 60 days. On any day your tracker has no session, Titan falls back to every other sleep source.
A per-metric choice overrides the tracker. Go to Settings > Health & Connected Apps > Data Sources & Integrations > HealthKit Sources > Sleep. If you picked a Primary Source or limited Allowed Sources there, Titan uses only those sources and skips the Sleep Tracker setting. There is no fallback in this case. A night your chosen sources missed stays blank. Tap Reset to All Sources to remove the limit.
044. Read the "Sleep tracked by" line
Tap the Sleep card on Today. Under the score ring and your sleep target, the detail sheet reads "Sleep tracked by" followed by a source and, when Apple Health has one, a device. The source is the app that wrote the most samples in that session. The device is the one that recorded the most samples. "Sleep source unavailable" means Titan found no qualifying session for that day.
055. Check Health sharing
Titan reads sleep from Apple Health. Wear your watch to bed, and make sure your sleep app writes sleep to Apple Health. Then go to Settings > Health & Connected Apps > Health Permissions, which opens iOS Settings for Titan, and confirm Sleep is allowed. If Titan cannot read sleep, it shows no sleep. It shows no error. Some trackers write duration without stages. Titan can still give those nights a simpler score based on duration. The health permissions article lists everything Titan reads.
If a night still looks wrong, send the date and the "Sleep tracked by" line through the contact page.
