Remeber that WLAN is a radio link. Ideally, the antennas should be able to radiate freely in all directions. Directly to the USB port of the TV are the conditions pretty much the worst of all variants. It makes sense to first use a USB extension cable into the port to connect, and then remove the stick in 1-2 meters distance from the "Störnebel" of the device and the shielding areas. The reception will improve.