ADXL362 Motion Switch Issues

I am using the ADXL362 as a motion switch to turn on the uP in my design. The following sequence works on most of the devices. They are all built the same. 

For the most part the units work and are turned on with motion and turn off with 3 min of inactivity. However, some devices never turn off. I can read and write to the parts the exhibit this behavior. Some devices work for a month or so and then cease to turn off, draining the battery on customer products. Has anyone experienced this issue?

****When INT1 is low, the uP is ON***

*****The INT1 pin is pulled low with a pulldown resistor to ensure default state of uP is on.

2) The uP programs the following to the ADXL362: 

Write to 0x52 to register 0x1F - Reset 

Write 0xF4 to register 0x20 - Set Activity Threshold

Write 0x01 to register 0x21- Set Activity Threshold

Write 0x00 to register 0x22 - Set Activity Time

Write 0x96 to register 0x23 - Set Inactivity Threshold

Write 0x00 to register 0x24 - Set Inactivity Threshold

Write 0x38 to register 0x25- Set Inactivity Timer

Write 0x04 to register 0x26 - Set Inactivity Timer

Write 0x3F to register 0x27 - Configure motion detection in loop mode and enables reference activity and inactivity

Write 0xC0 to register 0x2A - Map awake bit to INT1 and make it active low

Write 0x0E to register 0x2D - Begin measurement in wakeup mode and enable auto sleep