LiPo power supply Arduino

I have a LiPo battery (3.7v), which I connect to the 5v pin on my Arduino Nano, and my project contains a GSM modem (SIM 800L).

My problem is that the SIM module is able to send SMS messages, but fails to sent HTTP requests, as soon as I hit the reset button on Arduino, everything works fine.

What's the difference between manually connecting 5v input to battery vs having it already connected and hitting the reset button?

Alright, things got clear now.

The problem was the GSM module, I didn't wait for it to initialize (possibly GPRS part) in my setup function, so logically, when I was resetting, it was having it's time to initialize properly.