I’m using a 4k TV as a second screen and I have confirmed that neither Edge or Opera display 4K. According multiple sites it’s detecting my resolution as 1080p despite having a 4k resolution and HDR enabled in the settings on windows 10. My monitor however, which is 1440p currently is detected as 1440p so what’s going on? I can’t get the 4k content from my accounts I use for streaming like Netflix for example.
your TV likely can’t support more than 1080p when used as a monitor. see owner’s manual