Neither do I.
I have played with trackers a lot. It is absolutly essential to be sure the GPS is providing valid data in the first place. That it the reason I posted this response earlier;
> And why my result does not work ??? You tell us. When your code decides there is a new GPS fix\update and assigns the variables flat and flon from the GPS library what are these values ? You are printing them out ? You need to be sure the values you are getting from the GPS and sending are valid, before you need worry about what appears in the TTN console.