About the gps setting problem

hi. i have a em7430 module in hand ,I use it on win 10 system.
Looking at the AT!GPSAUTOSTART command manual, it is described as follows.
Parameters: <function> (Enable / disable the feature)
• 0 = Disabled
• 1 = Enabled at boot (GPS tracking session starts automatically when modem is reset)
• 2 = Enabled when NMEA port is opened

I tested the gps with the function =1 , in the open area .I can get the cuttent location on the window10 map.
but when i entered the room with the poor GPS signal . I can not get the location on the window 10 map.
but I found if I set the function value=2, value 2 is much faster to get the current location on the map than Value 1… A problem occurs when the setting value of GPSAUTOSTART is 1 ,I can’t get the the current location .It does not occur when the set value is 2.
as I understand ,the Function =1 mean the GPS start when the win10 system is power up.
the function =2 mean the gps start when the app software such as MAP is running
please give the explainaton for the the function value =1 and 2.

thanks a lot

value =1 means GPS engine is started when module is powered up
value=2 GPS engine is started when NMEA port (GPS port) is opened.

If you are on Windows 10, some location sensor may be used that communicates with the module not through NMEA port. You may check if your app uses NEMA port directly or not.