My new 4K+ never shuts the light off. All my other ones work correctly. I have done a physical reset twice.
The problem is that I use this on a smart tv because the remote is easier to use at night. Unplugging the tv, cures the issue.
Disable the automatic power saving. Settings/System/Power/Auto power savings, UNCHECKED.
You may also need to disable the screensaver. Settings/theme/(right-arrow)/Screensaver start time/Disable screensaver.
The problem is that I use this on a smart tv because the remote is easier to use at night. Unplugging the tv, cures the issue.