Well, this is annoying. I just wrote a long comment and when it went to make me sign in I lost it. You would think there would be a save mode when that happens. DOn't really feel like typing it all out again but Im frustrated as hell and I have yet to find a fix.
June 27 2018
We have 3 Chromecast devices in our house. All three show up in Google Home as active and ready to cast but the main room device does not show up in any of the regular streaming apps we use. We know it is not a phone issue because it happens on my husband's phone as well as mine. It also happens on my laptop running Chrome. We re-booted the device a few times. We switched devices from another room. We re-booted the router twice. Now, when we re-booted the router, the device on the problem area tv kept trying to connect to the wrong Wi-Fi network. I think it might be trying to connect to the network name we had before we got a new router several years ago. It's hard to remember those names but it seemed familiar. Meanwhile, the network on my phone switched from my FIOS network to the Chromecast network from the device in the bedroom which is the network that is working. I hesitate to say 'device' because we tried to different devices on the main network --the tv in our living room. We powered the tv off/on several times and my husband, a audio/video professional doesn't think the tv would be the issue anyway. The device on our main tv is plugged in via the USB. On our bedroom tv, it is connected via HDMI. I'm wondering if this is where the issue is. I meant to also say that the main Chromecast screen DOES show up on the tv with my preferred background settings. Again, it also shows up in the Google Home app. It just doesn't appear in Hulu, Netflix, Google Photos, or Youtube. I haven't tried any of my other Chromecast-compatible apps. I think all the other HDMI slots on the main tv are occupied so I can't test the HDMI theory just yet. I'll make some switches later and see if that works. I hope they fix this bug soon.
ETA: My husband had this to say regarding it being a possible HDMI issue:
"All the Chromecasts connect to the TVs via HDMI, but are powered by USB. The 2 on the Samsungs are powered (when the TV is on) by a USB connection in the TVs themselves. The Sony's Chromecast is powered by an external power strip, which is why that Chromecast can turn the TV on when you select it. The others wouldn't be able to do that."
I can use Chromecst just fine from the YouTube app on my iPhone, but not from my computer. I keep getting the "No Cast destinations found" message. I've tried all kinds of things to enable it, to no avail. The original Chromecast was so much better.