I was awake between 2am and 4.13am last night. I had gone to bed at 10.45pm, fell asleep within a few minutes. I awoke at 7.22am this morning. Fitbit told me I had two sleep periods, one from 12.45am to 2am, and one from 4.13am-7.22am. It showed deep sleep from around 4.30am for a reasonable period. I updated my sleep to show start time of 10.45pm and end time of 7.22am. It correctly input my middle of the night wake time but my 4.30am deep sleep disappeared. It identified deep sleep from 11.19pm-12.44am. How can some deep sleep disappear, how can some of my sleep not be recorder and, when I do record it manually how can I suddenly have over an hour of previously non existent deep sleep?
