nrf9160, AGPS works longer than GPS

[Stas Jis]

We use nRF9160 on our own board.
The firmware "Serial lte modem" is installed on the chip with a connection to an external MCU (#define MQTT_MESSAGE_BUFFER_LEN 8192)
We tested the environment with periodic switching from AGPS to GPS.
And in tests, we constantly see that the operating time with AGPS is twice as long as with just using GPS.

Average waiting time when using AGPS: 1 minute + 10-15 seconds;
Average waiting time when using GPS: 30-40 seconds.

What could be the reason for such behavior? It was expected that the operating time with AGPS would be significantly faster than with GPS.

The command sequence for AGPS:
AT+CEREG=5
AT+CFUN=1
AT#XNRFCLOUD=1
AT#XAGPS=1,1

The command sequence for GPS:
AT+CEREG=5
AT+CFUN=31
AT#XGPS=1,1

The tests were carried out statically, without movement.

[Roman1982]

one more thing 

we testing TELIT GPS performance and the time for a LOCK with assistant GPS is standing on 20 sec.

(of cause they also have a wikipwdia about the idle modes etc.. but on the field we observe match better performances)

this lead me to understanding that we are doing some thing wrong and we need your assist to define the shortest way to have a GPS lock and sending this information to the cloud. 

Thanks in advance ,

waiting for your respond