Cannot connect to Chromecast from Macbook Pro

Knowing how these streaming services work, I would suspect something is running afoul of some digital rights management scheme. A VPN would definitely cause that, as would screen sharing or anything to suggest the casting device is not compliant with those overzealous requirements. Even an external monitor might not work. Netflix (to cite a bad example) insisted the built-in display of my MPB was not HDCP-compliant which is of course utter nonsense and one of several reasons I completely gave up on them a while ago.

Try that Google help site: No Cast Destination Found? - Chromecast Help

John Galt wrote:

Knowing how these streaming services work, I would suspect something is running afoul of some digital rights management scheme. A VPN would definitely cause that, as would screen sharing or anything to suggest the casting device is not compliant with those overzealous requirements. Even an external monitor might not work. Netflix (to cite a bad example) insisted the built-in display of my MPB was not HDCP-compliant which is of course utter nonsense and one of several reasons I completely gave up on them a while ago.

Since someone else bumped the thread, I'll add to your good comment …

Especially an extended monitor attached using a "workaround" technology like DisplayLink or its competitors. I believe that sometimes, when you're using those, DRM-infested stuff might refuse to play on ANY display - not just the ones connected in a second-class way, but the built-in one, as well.

Say, because the driver for the second-class displays needs to have Screen Recording permission to get content from its virtual displays to the "magic decoder ring" in the external hub/adapter – and the DRM assumes that this "proves" you are a dirty thieving pirate up to no good.

Chromecast is a Google product, so if it is not working then you need to contact Google for assistance. The links in that Google Support document describe how to do that. Apple cannot fix a Google product.

Did you ever get this working?

You say your issue is the same as that older (locked) discussion, but that person was fine until installing the Cisco VPN client (even after uninstall, but...). Sadly, no one ever told that poor soul to do this (same thing happens and same setting is needed when trying to print to a wifi printer also on the local wifi):

https://www.cisco.com/c/en/us/support/docs/security/secure-client-5/221024-configure-local-lan-access-for-secure-cl.html

If you are also using a VPN client, that's definitely an issue, as the point of the VPN is to virtually make a private network between your device and the destination server to which the VPN client connects, isolating it from the local network or ISP's network (without setting otherwise, as per the Cisco link, above). This would be true of any VPN, not just Cisco's (depending on how any given VPN client handles local network access, like Cisco's checkbox preferences option does).

Otherwise, just a thought, but what macOS is your MacBook Pro running vs. your iMac?

This thread pre-dates Sonoma, but similar symptoms as our different issue, where all of our Sonoma Macs can see our single Chromecast perfectly fine 100% of the time, but a 4K Apple TV -also on the same network, and all of which has worked perfectly and seamlessly for YEARS!- is only seen rarely/intermittently by all Sonoma (14.5) Macs now. Monterey Macs still work 100% of the time without issue, and all on the same, otherwise fine network (run via Apple's last model of Apple AirPort Extreme no less). Haven't tried Ventura, but it's closer to Sonoma than Monterey, so we're hoping to find a solution before Monterey goes EOL later this year.

"It just works!" is clearly no longer anywhere near what it used to be -if in any sense whatsoever- with Apple products any longer...not just with a Google Chromecast.

That's all true, but only after you can even see the Chromecast (or Apple TV 4K in our Sonoma case) at all and then actually connect to it. At that point, after you see and connect to it, then it becomes a second "display" and DRM/HDCP may affect the output. This OP's issue here is more akin to, say, not being able to turn on a TV (i.e., see the Chromcast to conect to it at all), which is before you even get to any issue of whether or not the channel you want to watch is on your cable package, or, say, the streaming app on your smart TV is working and you have an active paid subscription, or so on (i.e., DRM/HDCP affecting the output).

Until the OP can even get the MBPro to see the external device at all (Chromecast), then nothing about DRM or HDCP-compliance will matter...

The suggestions from that Community Specialist are valid but the OP did not follow them correctly. Please describe what you did in an attempt to solve the problem.

Ok then. Best wishes.