This is what I have found using the Xhifter for a little over one week.
Before you start to ride if the Xshifter has been idle for hours or you install the battery you need to press the reset button on the Elink. It takes about 30 seconds for the Elink to “wake up”. At this point the pod will not shift the Elink.
To get the pod to communicate with the Elink, press & hold the pod reset button for 1 second then while still pressing the reset press one of the shift buttons for about 1 second then release both of them. In the time it took to read that sentence you could have done that button press several times. Once you have released the buttons, you will be able to shift in 2 seconds.
If the Xshifter has been idle for less than 30 minutes, the pod should still be connected to the Elink. If the pod doesn’t respond you can press the Elink button only.