Just so you know... that may not be about a clear transmission path... it may likely be about what mode the X1 was started in. I have that commander... it has a normal mode... and a close mode. If the commander is within 12 feet (iirc) and hasn't been turned on in close mode you'll start getting intermittent failures to fire... and the closer the two get the more frequent the failures become. More information: GODOX PHOTO EQUIPMENT CO.,LTD Download "Q: Why X1 can not trigger in near distance A: Please upgrade the newly version(X1C V15,X1N V16,X1S V13), long press the TEST button and turn on the power simultaneously until STATUS blink for 2 seconds,0-30m remote control can be selected." EDIT: This FAQ answer suggests it isn't 12 feet, but rather 30 meters.. which seems off considering that would be 100 feet.