Your payload must be formatted differently - can the type of gateway affect that?
If I take my payload string and manual copy bytes 6-9 (lat) and 10-13 (lon) and then paste each into https://www.rapidtables.com/convert/number/hex-to-decimal.html
the “Decimal from signed 2’s complement:” result shows the precise location of my tracker as verified by Google Earth.
I shouldn’t think the gateway makes any difference, but the sketch file loaded in your device certainly does. As I understand it, there are at least two versions floating around. One written specifically for the One V3 and a ‘universal’ one that works on multiple devices. I was not able to get the universal one to work correctly.
OK, I found the error, which was in my code for the mapping application and not the TTN payload Decoder. Sorry for this series of posts.
The following are correct for the version of Universal Tracker I am using:
var long = (bytes << 24) | (bytes << 16) | (bytes << 8) | bytes;
var lat = (bytes << 24) | (bytes << 16) | (bytes << 8) | bytes;