I'm not completely sure but betting different antenna for 5GHz than 2.4GHz. Again, figure out if you have 2.4 or 5. If it's 5, make it 2.4. Probably problem solved. At the AP the antenna should be straight up and down if external, although that probably only matters if your antenna in the laptop is straight up and down. It should pick the antenna by default. You probably don't need to mess with that. No real tweak you can likely do other than making antennas bigger or raising power levels.