Hey, i know this is an old topic but in case someone needs this like i did… I had the exact same issue but managed to solve it.
This problem is most probably due to the fact you did not enable LAN mode on your lights. And that is, because you are not using the Yeelight app. Here is a link explaining everything:
https://getyeti.co/posts/how-to-control-yeelight-and-your-smarthome-with-yeti
This indicated also on that page:
However, it’s indicated way too low in my opinion. Would be nice to push up that section so that people are better prepared !