I don’t know where to find a fix for this problem so I’m turning to the forum for guidance. I have previously successfully paired a Schneider Wiser dimmer CCT5010-0002 and it worked as expected with all needed functionality.
However, some days ago it lost its connection to HA and now I’m unable to reconfigure or pairing it after also trying resetting the device to factory settings. The dimmer still works with the physical button on the wall; on/off/dimming.
I’m running HA on a RP4 with RaspBee ii as controller and configured all Zigbee devices with the ZHA integration. Strange thing is that all other Zigbee devices are still connected and functioning. Where do I start?
I also highly recommended migrating to a newer Zigbee USB adapter (as Zigbee Coordinator radio) and connect it via a longer USB-extension-cable to a USB 2.0 port (not USB 3.0 port) instead of using an internal GPIO adapter like RaspBee (which will be more affected by interference than external Zigbee Coordinator adapters), especially if have any other USB 3.0 devices connected to the same computer.
In addition, use disable WiFi and instead use wired Ethernet to your computer for Home Assistant, as well as consider adding more Zigbee Router devices and maybe even buy a few dedicated Zigbee repeater / range extender devices to add to your Zigbee network to help it better optimize its mesh network functionality.
In essence, with Zigbee you need to understand that it is very important always keep in mind that relatively speaking Zigbee radios are extremely sensitive to interference. So simply adding more mains-powered devices that act as Zigbee Router devices and do everything to avoid interference will usually resolve most issues or at least hide many symptoms of noise environments in the same frequency range.
Just to help others in the same situation. My problem was the resetting of the SE dimmers to factory settings. The SE manual explains three short press and one long until the status light blinks red. However it did not reset the devices, you need to keep holding until the status light rapidly blink red (20 sec). After that all the devices successfully paired again.