Performance & battery · Performance modes
Why did Storage Studio switch to Light mode on its own?
Short answer: On Automatic, Storage Studio moves to Light when your Mac is warming up, the battery is low, Reduce Motion is on, or the Mac is very busy. It turns off live graphs, works gently, and returns to normal on its own.
With the setting on Automatic, Storage Studio moves to Light when there's a plain reason to be gentler: your Mac is warming up, the battery is low and you're not plugged in, Reduce Motion is turned on in macOS, or the whole Mac has been busy with very little spare processor time.
In Light it switches off live graphs and animations and does its background work very gently. A notice titled "Running light to stay out of your way" tells you which reason applied — for example "Low battery — saving power" or "Mac is warming up — effects paused".
Nothing is stuck or broken, and everything comes back by itself once the reason goes away. If you'd prefer a fixed level, choose one in the performance menu.