It used to grant me 75 calories for each hour of sleep. Now it gives me none. Paired with SmartWatch 3 - but the problem started recently, well after pairing the watch. I have never worn the watch at night.
I'm getting sleep calories on my S5. After reading your post, I checked my calories this morning on the phone and found 625, whereas I had not yet done anything except prepare breakfast.
Google Fit made no sense to me. It used to give me a standard, daily burn, and add any exercise I input manually. Now it doesn't. I quit using it since Moto Body is much more consistent.