TL;DR: It's moved to "Bluetooth and devices > Touchpad", not "Mouse"!
My workplace which instructs everyone to use the Guest account, recently "up" dated to Windows 11, and the "down motion scrolls..." option does absolutely nothing. Before, when they used Windows 10, I went into the settings every time to revert the inverted scroll direction, or use the TrackPoint to scroll the right way around.
The laptop is a Lenovo ThinkPad E15, which has a touchpad and a TrackPoint. The TrackPoint used to scroll down when I tilted it down, but now it also scrolls up when I tilt it down! It's a regression to my workflow! Again, changing the settings in the Settings app does absolutely nothing. I opened the Synaptics TrackPoint settings, and there was nothing there about scroll direction, so it's not because of that.
Then I had the breakthrough by typing in "trackpad" to the Start menu, which is now inexplicably in the center instead. That took me to the separate Touchpad settings menu, and the scroll direction settings there worked!
I still don't know how to revert the scroll inversion for the TrackPoint, but since I don't use the TrackPoint much, I could live with that.