all four bulbs having an ip and do work over Yeelight Android-app as expected.
The fourth bulb is connected over different WLAN SSID and therefore it seems to be the reason for it.
Network is build like this
router 192.168.1.15 with WLAN SSID1 -> 8 port switch -> AP 192.168.1.16 with SSID2 -> bulb4 192.168.1.17
Homeassistant running in Docker on OpenSuse is connected to same 8 port switch.
bulb1,bulb2,bulb3 connected over SSID1
Is that maybe some ipv6 issue? Must that be enabled separately in homassistant?
But since I can ping -v4 the bulb from any other device, it should work, right?