I buyed several Sonoff Zigbee devices, the first did pair immediately without any issues. After some days i tried to add some more by they did not get recognized. After lot of trials, resets and scans, i gave up.
And then sometimes it shows up after a long while. But i can’t find any rule. Even just waiting 6-8 hours makes no difference. The devices to be paired are nearby fully working ones. Mostly switches.
Any help would be good here!