GPS and accelerometer are always zeroes

Using Tracker One and examples from github

I can get battery readings, but location is never transmitted. Also, when I uncomment accelerometer, it’s also always 0,0,0. No matter how I shake the device.

I can see that GPS LED on the device is always OFF. However, it was ON before I switched to developer firmware.

What am I doing wrong and how it can be fixed? Thanks!