Hey there Bertilo,
I'm sorry to hear your Chromecast is running into some connection issues. Networking problems can be a pain, so I'd be happy to look into this. First, go ahead and match up your LED light to the one in this article, then let me know which one it is. Then, I would also follow the steps listed in this article, as this covers a lot of potential issues as well.
I look forward to your response, and if you have any other questions or concerns for me, please let me know!
It's us again. How's it going? Did you manage to get your Chromecast working? If you're still having trouble, please manually connect to the Chromecast SSID. Here's how: go to the phone’s Settings > Open Wi-Fi and connect to the Chromecast SSID (Example: Chromecast1234, Living Room TV, Bedroom TV, etc.) > Go to the Google Home app and try to set it up again.
I appreciate your help here, Jeran, Juni, and Dan.