Hello,
Something is wrong for sure.
One solution for some serious range is to buy a Module Amplifier from Shireen, or other sources, but you may need a license to operate. Anyone who is looking to some serious range with any FPV/ UAV needs one of these, plus the appropriate antenna for the application.
http://www.shireeninc.com/900-mhz-2-watts-oem-module-amplifier/
Now this one is the Bomber, if you can find one cheap.
I had one located on eBay a while back, but wasn’t ready to purchase, and it got away for about $175
Here is a quote from specs…
“Outdoor/RF line-of-sight range: up to 40 miles (64 km)”
Wow!!!
Good luck
Ted