I am seeing a very similar issue with AlarmKit on physical iPhone devices (Simulators no bug at all). Device: iPhone 15 Pro iOS version/build: iOS 26.5 Always On Display: enabled Low Power Mode: off Focus mode: off Repro steps: Create four AlarmKit countdown timers: 1 min, 3 min, 1 min, 4 min. Start them one by one: 1m -> 3m -> 1m -> 4m. Pause two short 1-minute timers from the main app. Lock the device and let it enter AOD / screen-off state. Do not tap, wake, unlock, or move the phone. Wait for the 3-minute timer deadline. Expected: The 3-minute AlarmKit timer enters alerting and rings at its scheduled time. Actual: Intermittently, the 3-minute timer does not ring at the deadline (~30% of the times). It may remain silent until the device is tapped/woken/unlocked, then the alarm fires late. The delay can range from ~20 seconds to several minutes. Notes: This reproduces only on real iPhone hardware, not reliably in Simulator. The issue appears after repeated rounds of scheduling / pausing / canceling timers. Rebooting the device temporarily improves the behavior. I have reduced app-side AlarmKit resync/cancel pressure, but the locked/AOD delayed delivery can still occur.