Open Radar

 
Summary:
When the startAccelerometerUpdatesToQueue of CMMotionManager is called:

Debug Builds (From XCode):

Accelerometer Updates will continue even when the watch face is off.

Release Builds (AD-Hoc or Enterprise):

Accelerometer Updates will stop when the watch face is off.

Steps to Reproduce:
1. Make a call to the startAccelerometerUpdatesToQueue of the CMMotionManager class.
2. Print the resulting data to the console so it is easy to see when data is and isn't being collected.

Expected Results:
I believe the correct behavior is that accelerometer data updates should stop when the watch face is off.

Actual Results:
The most common behavior is listed below, but the behavior can vary.

Debug Builds (From XCode):

Accelerometer Updates will continue even when the watch face is off.

Release Builds (AD-Hoc, Enterprise, App Store(Haven't actually tried an App Store build)):

Accelerometer Updates will stop when the watch face is off.

Version:
2.2 & 2.2.1

Notes:
I wasted a lot of time thinking my watch app was working because I got very consistent data when I was using builds created in XCode.  Once I put up builds using Enterprise distribution, my code completely broke because accelerometer data stopped when the watch face turned off.  This is a major time sink for developers since code using accelerometer updates can really only be tested using Release builds.

Configuration:
Watch OS 2.2
 iOS 9.3.1
XCode 7.3 

Watch OS 2.2.1
iOS 9.3.2
XCode 7.3.1