Questions/issues about Maxx Range antennas

[Blvk Phantom]

I have a Phantom 4 with the MAXX antenna. I do get a lot better range than with the stock antenna. One thing that i do notice is that the HD part of it (video tranmission) seems to loose contact a lot faster than the controller. I can go out about 11/2 miles before this happens. I do watch a lot of long range videos on YouTube where they can go almost 7 miles one way before they starr to loose any contact. Im trying to figure out the possible issues regarding the HD (video reception). Any ideas?