FYI: According to this post, it's because old (Gen-2) chromecast devices
have a built-in certification key that expired on March 9, 2025.
Presumably, after 10 years, nobody at Google remembered that this was
going to happen. The post says Google shou...
Same here. My Chromecast device is hard-wired (enet-usb adapter); I can
ping the device from my laptop and from my phone, but Google Home can't
see it, and (obviously) nothing can cast to it. It was working fine
yesterday.
