1. Could you please let me know in which state (whether it is in advertising state or in connected state) the device rarely enters into the low power mode ?
2. Could you please check with the AN92584.zip example projects (in different GATT Profile roles) and let me know your observations.
3. Please refer to the 'AN92584 - Designing for Low Power and Estimating Battery Life for BLE Applications' datasheet for more information on Designing of low power applications.