Softdevice is not advertising after switching from DM (device manager) to PM (peer manager)

Question

Hi, 
 SDK: nRF5_SDK_00.11.00 ; S132 SoftDevice v2.0.0 
 I am working now to migrate my application from DM to PM (in order to better handle pairing&bonding). 
 Sometimes the application will not start advertising, I start to advertise using: 
 static uint32_t augu_ble_start_advertising(void)
{
	uint32_t err_code;

	err_code = advertising_enable_disable_(1);
	if (NRF_SUCCESS != err_code)
	{
 AUGU_LOG_PRINTF_ERR("ERROR: advertising_enable_disable_(1) ; error code: %d
", err_code);
	}

	err_code = ble_advertising_start(BLE_ADV_MODE_FAST);
	if (NRF_SUCCESS != err_code)
	{
 AUGU_LOG_PRINTF_ERR("ERROR: ble_advertising_start(BLE_ADV_MODE_FAST) ; error code: %d
", err_code);
	} 

	return err_code;
}

but in the cases that adv is not starting, I am not getting ANY advertisement event (none of the below printouts are showing) 
 
 void augu_on_adv_evt(ble_adv_evt_t ble_adv_evt) 
{
	switch (ble_adv_evt) {
 case BLE_ADV_EVT_IDLE:
 AUGU_LOG_PRINTF_WRN("ADV EVENT: BLE_ADV_EVT_IDLE (%d)
", ble_adv_evt);
 augu_ble_main_fsm(AUGU_BLE_FSM_EVENT_ADV_IDLE);
 break;

 case BLE_ADV_EVT_SLOW:
 AUGU_LOG_PRINTF_WRN("ADV EVENT: BLE_ADV_EVT_SLOW (%d)
", ble_adv_evt);
 break;

 case BLE_ADV_EVT_FAST:
 AUGU_LOG_PRINTF_WRN("ADV EVENT: BLE_ADV_EVT_FAST (%d)
", ble_adv_evt);
 break;

 default:
 AUGU_LOG_PRINTF_ERR("ADV EVENT: received unhandled ADV event (%d)
", ble_adv_evt);
 break;
 }
} 
 
 This happens most often after flashing the application - it will not start advertising (only after 2-4 reset cycles) 
 I am looking for the root cause of that because I am not sure it will happen only after flashing, and I surely don't want to solve it with a patch. 
 BTW, 
 I tried to start to advertise in a loop (some kind of while until I get the 1st event) but after 8 retires still adv didn't start (only resetting the device 2-4 times solved this) 
 Best regards, 
 Erez.