I use a Chromecast device on my TV. This has worked fine untill I accidentally removed the TV from my Home app. Indeed, TV is no longer visible in my Home app, but the message "Install Chomecast" is now present in the app. I tried to do that, the candidate "TV" is correctly shown and the app can connect to it. Next step is connecting to my WiFi. That fails with a message like "Another user has set up this device" (after translation) and I am closed out without any option to go further. I have disconnected and reconnected power of the Chromecast device but that doesn't help.
Answered! Go to the Recommended Answer.