Data Sources for Sleep Tracking in Health App

I use the AutoSleep app to track my sleep. In the Health App, AutoSleep is at the top of the priority list of Data Sources, followed by my Apple Watch and iPhone. According to the Health app, "when multiple sources are available, one data source will be chosen based on the priority order listed". This implies to me that the Health app should follow the data provided by AutoSleep and then share that data out to the apps I have set as "allowed to read data". This doesn't seem to be working properly.

An example from last night:

• AutoSleep shows that I slept 8hr 2min
• From within the Health app, if I check the AutoSleep data (at the top of my Data Sources list), it does in fact show 8hr 2min.
• However, the sleep data within the Health app itself is showing 9hr 1min.
• 9hr 1min is also what's being shared out from the Health app to my other apps (e.g., Lose It! app for tracking calories).

The 9hr 1min number seems to be coming from my Apple Watch itself, which is listed as the 2nd priority for sleep data.

I want to use AutoSleep as the primary (and only) data source for tracking sleep. Based on the language in the Health app, this should already be the case as long as it is listed at the top of the Data Sources list and syncing properly (which it is).

I can't find a way to tell the Health app to actually prioritize AutoSleep data or to completely ignore my Apple Watch and iPhone sleep data.

Why is this happening?