Ahh that's good to hear they've fixed it! Thanks for providing that info. This malfunctioning night-light has been a real nuisance since upgrading to 1903 on both my machines. I have to do a full re-start to get it operational again and for the temperature slide to work. Hopefully we'll get that fix soon on the normal ring (whatever non-insiders are called!)
This is not the first time Microsoft has broken night light when they issued a major update like 1903. I sure hope the normal distribution channel will get the fix soon. It's a real PITA to have to sign in, ensure night light is enabled, then sign back out and then in again to get night light to work. But at least that's a workaround until Microsoft gets their (full) act together.
Disabling fast boot in bios fixed it for me. I'd rather have night light than save a few seconds.
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