The bug:

The 20w46a changelog includes:

Buttons that change value (like Difficulty) can now be controlled with mouse wheel

This works in some option menus, but not others. I was able to reproduce this on a PC running Windows 10 as well as a MacBook Pro running macOS 11.0 (using both the scroll wheel on the mouse and the MacBook's trackpad).

Steps to reproduce:

1. Open one of the options menus listed below as working correctly.
2. Use the scroll wheel or trackpad while hovering over a button that changes options.
    The button will change value appropriately.
3. Repeat steps 1 & 2 for a menu listed as working incorrectly.
    The button does not change value.

Affected menus:

Menu	Scroll Works
Main Options
Skin Customization
Video Settings
Language
Music & Sounds
Controls
Mouse Settings
Chat Settings
Accessibility Settings
Add Server
Create New World
More World Options