Windows 10

On February 1, 2024, on Windows 10, the version of OneNote installed from the store was upgraded to version 2401 (build 17231.20182), and the UI changed back to the old UI.

The main thing is that the page list pane of OneNote is not always white, but changes back to the same color as the section.

The icons of the sections have been changed from the new vertical icons to the old horizontal icons.

Even if the Office theme is set to "white" in the options window, the page list pane is still colored.

At the same time, the "Vertical Tab" function doesn't work, click on it, and you can't switch to the vertical tab.

Windows 11

And the same version, in Windows 11, is the new UI， and the old UI is not returned.