What Zigbee channel do you use? I have 18 or so of these and when I first stated my HE journey 3 years ago I was on an odd channel and I had a hard time pairing them. After moving to 20 they worked fine. Obviously this will impact all your other Zigbee devices and changing channels will cause them to take several hours to find the change.
Here is that dialog. The ST sensors are rebranded Centralite so same thing.
