Tahoe 26.4: Screen brightness increasing without user intervention

By Donal, 6 April, 2026

Forum
macOS and Mac Apps

Hi all,

Am noticing odd behaviour on my MacBook Pro running Tahoe 26.4. I keep my screen brightness at 0%, however I am noticing several distinct anomalies:

1. Sometimes when I press FN-F1, Vo reports screen brightness at 6% after the first key-press, then 0% thereafter.
or
2. Screen brightness seems to auto-increase to 35-40%, without any intervention from me.

In other words: it does not remain at the 0% value at which I set it. Anyone else encountered this? Nothing is showing in System Settings which suggests an issue there.

Options

Comments

By Maldalain on Monday, April 6, 2026 - 17:00

It will always change even if it is at 0%. Lower brightness to 0% and switch on screen curtain. This is how it won't change.

By TheBlindGuy07 on Monday, April 6, 2026 - 18:40

That changes brightness depending on the lighting around. And of course @Maldalain is right.

By Donal on Monday, April 6, 2026 - 19:52

Yes @TheBlindGuy07, I would have assumed that turning TrueTone off would solve it, but alas not. thanks @Maldalain, will give your suggestion a go.