I have a pair of Yongnuo rf605n wireless flash trigger transceivers and can not (despite several hours of trying) get them to fire my Yongnuo 568ex flash off camera. I have one mounted on the camera (Nikon D750) and one on the flash mounted off-camera. I have set everything to same group and channel. There seems to be some communication between the 605's but the flash will not fire when I snap the shutter. Even if I take the camera out of the picture and just try using the 605s and the flash by themselves it will not fire. Also, the flash will fire in the optical line of sight mode using the camera's flash and the 605's work fine as shutter triggers.
What can I do about this problem?