This means that the device is paired and the Zigbee connection is OK....
Can you try the Tuya 4-in-1 driver?
Manually install (or update to the latest version) of the Tuya driver, enable the Debug logs, then pair the Sonoff sensor again (without deleting it). I will need the live logs from the pairing process.
Yes, the 0x0406 cluster is new, most probably it is used to send a binary 'light' or 'dark' illuminance switch, Sonoff used this in some of their other products.
