Sleep tracking kicked in a couple of hours later than actual

If you are just looking to fix that record you can do it in the Garmin Connect app. From the dashboard on iOS click in the box that displays the sleep data. From the detailed sleep record screen that appears next click on the stacked three dots in the top right of the screen and then select Edit. From there you can change the start and end times of your sleep 

Sleep tracking isn't done on the watch, it's done on the servers when the data is uploaded, and the configured sleep/wake times are used.

Am I reading that correctly, the watch doesn't actually track how long you have slept but some pre-configured time?

So if its programmed to track sleep from 10pm - 7am and I fall asleep at 11pm and wake at 9am it wont track it?

The pre-configured time is when it pays attention to you sleeping or not. I think it has more to do with the garmin servers analyzing a limited set of data (analyzing is not on the watch) instead of the whole day. It also tracks way further than you pre-set wake time. Mine is set to wake up at 8am, after a heavy day i sometimes sleep to 13.00, it tracks it fine.

Where the pre-set time do come into play is when pluse ox metering is set during sleep, it starts and stops measuring only during these pre-set hours, this is also true for 'do not distrub' during sleep hours.

Well I did not go to bed still up at 2am but it is telling me I slept 8 hours! So not accurate is it? Just wonder if the rest is as bad