I have encountered an interesting issue with Chromecast. Sometimes it works normally, sometimes it insists that it can’t find the device, which is on the same network, about 3 metres away. I posted about this previously because I couldn’t figure it out. Now I have finally stumbled on the answer by accident. It puzzled me for a long time. Maybe someone else has run into the same thing.
I use a Chrome browser on several Windows laptops. I usually keep the laptops turned on all the time. I have them set to go into sleep mode when the lid is closed. When I want to use one I just open the lid and it comes back on after a few moments. The wi-fi also reconnects after a brief delay.
What I have discovered is that Chromecast usually cannot find my cast device when the laptop is restarted this way. Everything else appears completely normal, but no cast device can be detected. What I have to do is close the Chrome browser and reopen it each time. Chromecast then works normally. If anyone else runs into this, that seems to be the answer.