Use the actual supported web service
Sign in only through the service’s genuine web address and check its browser/platform support. A private playlist URL is not necessarily a browser-ready player page. The site must provide an appropriate playback interface and supported media delivery.
Chrome’s help distinguishes browser updates, extensions and stored site data as possible parts of video troubleshooting. It also notes that retired Flash content is no longer a working playback route. Do not install a Flash replacement promoted by an unrelated download page.
Keep the first comparison narrow
If a video fails, record whether the page loads, sign-in succeeds and the player produces an error. Compare a supported clean browser session or the service’s documented troubleshooting route without erasing unrelated browser data first.
Clearing site data can sign you out and remove preferences. Record what is needed to restore the legitimate session before changing it. Do not turn off browser security or accept a certificate warning merely to make an unverified source play.
Choose the right Cast operation
Chrome can cast a tab or screen to an appropriate receiver, while Cast-enabled sites may offer their own media handoff. Those paths are different and can use different controls. A working computer video does not guarantee the same receiver supports the service’s Cast route.
Keep the computer and receiver on the required local network and verify the actual destination. If no receiver is discovered, diagnose discovery before changing the subscription account.
Make a useful browser record
Record Chrome version, operating system, page address without private tokens, error wording and whether the problem affects only that service. This is more informative than saying every browser or every IPTV source is incompatible.