I purchased a new 600-EX-RT and the new ST-E3, right out of the box everything worked perfectly and as expected. Turned both units off from testing and went out to use in real life and they will not link together. If I turn the transmitter on first, then the flash, the flash link light will stay yellow while the transmitter goes green. If I turn on the flash first and then the transmitter then the transmitter will go yellow and the flash will go green. What am I missing? I've done no custom functions, both are set to the same channel and both are set to the same ID.
Any ideas, I'm going bonkers trying to figure it out.