Controller keeps flashing in green and disconnected

I just received the product and try to use it for the first time. But when I turn on the controller it just keeps flashing and cannot be connected to the system. I’ve tried to restart the whole thing several times but it still doesn’t work. What should I do in this situation? Anyone can give some advice on it?

This sometimes happens on my old compute unit too. I usually get it to work by leaving the controller attached to the compute unit and then press the trigger pad and hold for a few seconds, repeat this several times, and then remove the controller. Most of the time the green light will stop flashing and stay on. Try this and good luck…