Chromecast issue

[J-M-7]

Apologies for being kind of long, but I'll try to be succinct. I have looked through common troubleshooting, and nothing has helped so far, or does not seem to apply.

We've had a Chromecast for a while, and it's always worked great. (I don't honestly know what generation it is, but we've had it for 3 or 4 years at least.) We just switched our ISP to Gfiber and are having some issues. If my roommate sets up the device, it appears to work fine, but no one else on the network can see or use it in any app. If I set it up, it takes a long time but seems to go alright, until the very end when it gives me an error message that says:
"Your Chromecast was setup successfully but can't be found. Make sure your mobile device and Chromecast are on the same wi-fi network. - Turn off AP isolation. If AP isolation is enabled on your wi-fi router, you will need to disable it."
The Chromecast will display the normal screen as if it is connected, but no one can find or use it. We've tried it on both the standard wifi and the 5 ghz, same exact thing.
If I plug in the old isp/router everything works just fine.

It doesn't make sense that it's a router setting, since my friend can activate it just fine.
Doesn't make sense that it's a hardware issue, since we can both connect to the new wifi other than the chromecast, and we can both connect to the chromecast on the old network.

Using Android phones.
Gfiber account is in my roommates name, which I suspect might have something to do with it, but IHNI.

[Muhim]

I've been struggling with this for a month now!
Today I gave up and ordered another product, not from Google

[virnab]

Hi J-M-7,

Thanks for reaching out to our community.

I understand that you have had a Chromecast device for 3 or 4 years working flawlessly, but when you switched your ISP to GFiber, you have been having trouble trying to connect it and stream again. I highly appreciate all details provided to better understand your experience and important information such as the message you receive when you try to set it up: "Your Chromecast was set up successfully but can't be found. Make sure your mobile device and Chromecast are on the same WiFi network. Turn off AP isolation. If AP isolation is enabled on your WiFi router, you will need to disable it." No worries, help is here.

To better assist you, I would appreciate it if you answered the following questions:

• What model of Chromecast devices are you using? You can use this help center as a model reference: Chromecast and Google TV Streamer specifications
• What's the make and model of the mobile device you used to cast?
• What's the LED light status (solid or flashing white)?
• What's the distance between the router and the Chromecast device?
• Have you tried to reboot your mobile device?
• Have you tried to reboot your router?

Regarding the message that you’re getting, it is letting you know that the current WiFi network configuration is preventing your mobile device from communicating with your Chromecast, so you need to disable AP (access point) isolation on the router. Here are some recommendations to consider:

• If you don’t know how to disable AP isolation, please refer to the GFiber documentation or router manufacturer for assistance.
• If you don’t have access to the GFiber router settings or are trying to connect through a guest, hotel, or public network with AP/client isolation, you won't be able to set up the Chromecast device.
• If you are trying to connect through a WiFi extender, please check the extender settings. You will need to disable AP isolation on the WiFi extender before they can set up the Google Cast device.

Please keep me posted.

Best regards,

Virna

[J-M-7]

Sorry, I've been away from my computer for a few days.
I'll have to check my chromecast later for some of those details, I should be able to post it here shortly.

For now:
*I have tried to restart both the router and mobile device.
*The router is about 50 ft from the chromecast. It connects just fine when my roommate does it, but not when I do. It's just that if he sets it up, I then can't connect to it, even though he can.
*We're trying to connect it to our personal network, directly from the router. No wifi extenders, no connecting through guest networks or anything.
*The Gfiber router does not seem to have any AP isolation options. I've been into the settings, and there is nothing I can find that looks relevant.