Hello,
This may be normal behavior once correct connection management code is in place, but I want to verify since originally I was looking at 2-3 minute connection times on power cycles. Since combining the following steps upon a disconnect request in my code, the nRF9160DK I'm using will reconnect to LTE after wake-up or complete power cycle in a matter of seconds. I'm very much pleased with this, but I want to ensure it's correct behavior... I've went as far as leaving the board disconnected from power for days and it will still power up and connect very quickly.
lte_lc_offline();
lte_lc_power_off();
bsd_shutdown();
nrf_regulators_system_off(NRF_REGULATORS_NS);
After this process was implemented for disconnecting, I can power cycle or manually trigger a wake up and the module then does the following:
lte_lc_init_and_connect();
The init and connect completes in 3-10 seconds and I'm online passing data without issue.