Device: Forerunner 70
Firmware: v9.17
Frequency: High (4–5 nights a week)
Issue Summary
The sleep tracking algorithm completely wipes the first 2–3 hours of sleep data if I wake up briefly (5–10 minutes for a glass of water or bathroom break) early in the night, specifically between midnight and 3:00 AM. Instead of logging this as a brief awake period within a continuous sleep session, the watch treats the wake-up as the start of my sleep, entirely deleting everything recorded prior to it.