I have used this vTX in other builds before without issue, but for some reason suddenly when I try it in this build, it has this issue. I can only start video transmission, and that does work fine. All other functions do not work. It doesn't display the blinks to show settings, and I can not change the settings. I think it is a firmware issue, and am wondering if it is possible to re-flash the firmware to fix it. Otherwise I'll try to get a replacement sent.