On iOS 26.2 (23C55), DeviceActivityMonitor.eventDidReachThreshold fires intermittently for a daily schedule (00:00–23:59) even when iOS Screen Time shows 0 minutes for the selected apps that day. This causes premature shielding via ManagedSettings.
Environment: iPhone 13 Pro Max, iOS 26.2 (23C55). Event selection: 2 apps. Threshold: 30 minutes. Multiple TestFlight users report the same behavior across various app selections and thresholds. Intermittent (~50% of days); sometimes multiple days in a row. Not observed in testing prior to iOS 26.2.
Evidence: sysdiagnose + Screen Time screenshots (with 0 screen time on selected apps) + unified logs show UsageTrackingAgent notifying the extension that “unproductive from activity daily reached its threshold,” followed immediately by ManagedSettings shield being applied (extension reacting to the callback).
Filed Feedback Assistant: FB21450954.
Questions: Are others seeing this on 26.2? Does it correlate with restarting monitoring at interval boundaries or includesPastActivity settings?