I recently decided to "retire" all of my older Google Chromecast "dongles". I purchased 3 new Google 4K streamers in addition to the one I already had. Even though I have a very capable full-stack Omada "pro-sumer" network, I intended to use ethernet connections. I then stumbled into a real mess.
On the first attempt, I set up the hardware exactly as expected, including connecting the ethernet connection. While the setup process began appropriately on my Samsung TV, the Google Home App on my phone failed to authenticate the Chromecast device, and did so every time I tried the QR code. There were no helpful instructions in any of the "help" prompts. I did some digging with Gemini, which suggested disconnecting the ethernet and starting over on WiFi. Unfortunately, I couldn't get that to restart properly, so went with the full manual TV setup mode, entering WiFi, Password, UserName, etc., using the Chrome control via the TV. Then I shut the Google, TV, and Samsung phone down and restarted, and finally Google Home synced to show the device, instead of complaining about not being on the same network.
Lesson learned, I went to the next unit and left the unit disconnected from the ethernet connection and everything was done in a few minutes, just as expected. Additionally, the full software download occurred after the handshake, authentication, and setup had occurred, rather than as one of the first steps.
It would be wonderful if Google would remedy this issue, or else include a "popup" that says "disconnect ethernet until setup completes".
I'm posting in the hope that this will be of value to other users.
Baseline system is Arris SB8200 > Omada SG205v2 > SG2016P | 2 x SG2008P | > 4 EAP610 access points. Typically about 50 client devices online, and almost half of those are from Google.
