sorry for late reply.
I just test sending command from telnet if the bulb is unavailable in home assistant.
The ‘toggle’, ‘set_power’, ‘set_rgb’, ‘set_bright’ etc working, command send to bulb and bulb response and change state successfully.
But the ‘get_prop’ has no response. I suspected that the ‘get_prop’ command has some problem. This is why home assistant failed to communicate with the bulb so after some time of idle, connection closed and become unavailable.