Similar to this question, my custom CSS styling for my Styled Media Receiver (SMR) doesn't get loaded on my Chromecast 2 device. Yet, the CSS is loaded and displayed correctly in the preview in the Cast SDK console.
I have saved the app in the console and waited for it so switch from "Publishing" to "Published". My Chromecast's serial number is also registered and shown in the console as "Ready for testing". I have double-checked that I'm using the correct App ID in my app. The Styled Media Receiver app just loads on the Chromecast device with the stock styling, i.e. it only shows my app's name.
The content of my very simple CSS file:
.logo{
background-image: url(images/icon.png);
}
.background{
background: rgb(6, 3, 46);
}
My CSS file is hosted on my website (hosted by InfinityFree), with a SSL certificate signed by Let's Encrypt Authority X3. I even left it overnight, but nothing. Yet, the Cast SDK Console loads and displays the CSS ok.