Night Light won't pair or group

A set of three night light, not pairing - attempted several times.
All set to Auto, flashing together for 30 sec, but each one works individually, not as a group.

I didn’t have this problem. I turned them all off and then I turned two of them to Auto and waited for them to stop blinking. At those point the two were linked.

I set the third one to Auto and it blinked by itself (the others were already set up and weren’t modified.

If give it another try.