Lg p760 connecting issue

today I got lg activation for Octopus now box is activated now when connect phone first dial 3845#*760# get port setting in port setting select Cp reset click ok but when go back in setting automatically option set on NO RETENTION I do use usb cable for this process please help me to get sorted this issue software log below while connecting phone .

Platform: LG Infineon
Connection mode: Modem
Selected model: P760
Initializing device…OK
Please, power phone ON, connect P990 cable (with 56k resistor), type
3845#*760#, go to "Port Setting", select "CP Reset" (or "CP Image
download") and click "OK"…

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