I think I have finally figured out whats up with the Oura sleep issues. Their API is broken. If I call the sleep endpoint with start_date=2026-08-19 end_date=2026-08-20 I get data for only 2026-08-20 (no 19th). If I call it with start_date=2026-08-18, then I get data for the 18th, 19th and 20th! Those parameters are supposed to be local dates matching the day field on the returned objects. Anyway I have worked around this by going back an extra day when a long_sleep webhook is received.
Please watch for the next few days and post here if your sleep is still not arriving promptly.
Thanks for the detailed report.