Google home some lights "don't react"

Hi,

I have set up Google Assistant manually according to the documentation (https://www.home-assistant.io/integrations/google_assistant/). I got it working and my lights are exposed to the Google Assistant / Home app on my smartphone. However 2 / 5 lights do not work from Google Assistant, they are shown as “Reagiert nicht” in my german app which translates to unresponsive or doesn’t react… The lights do of course work flawlessly from HA!

I’m struggling to debug this, I tried to resync using my Google Home Mini telling it to resync my devices multiple times. I have waited a day now to see if things sort themselves out, unfortunately they didn’t.

How can I debug this issue?