My laptop can cast to my Chromecast, but only after something else (like my phone) begins casting to it. Until the second something else casts the laptop shows 'no cast devices found', and the second the phone begins casting it appears to the laptop - at which point I can disconnect that and connect the laptop.
Any idea what is going on here? There’s only one Wi-Fi network, though it does have 2G and 5G - don’t know if that’s a factor. Seems super odd.