GPS usually does not work when not found NB-IoT nrf9160 tracking

[haohv6]

I am using nrf9160 for a monitoring project using NB-IoT network. The problem I am having is when I go to an area where there is no NB-IoT network, the device crashes often and GPS does not work (or is blocked and unblocked often).

What command should I use to prevent GPS not working when going into areas without NB-IoT networks

I see AT + Cfun = 20 (for deactivate) and at + cfun = 21 (for active) but these cmd respond quite slowly.

thank you

[haohv6]

I have solved this problem, I added at + cereg = 0 and at + cfun is not responding slowly anymore.