The Firefox 109 Release Notes inform us that:
>On macOS, Ctrl or Cmd + trackpad or mouse wheel now scrolls the page instead of zooming. This avoids accidental zooming and matches the behavior of other web browsers on macOS.
To revert to the previous behavior (zoom in/zoom up), users need to go to about:config and set mousewheel.with_meta.action to 3.
Most users don't read the release notes, know about about:config, or even join support forums. This change should've been applied only to new profiles.
For anyone stumbling across this thread who needs more help with changing the setting, here's the article on using about:config: https://support.mozilla.org/kb/about-config-editor-firefox
Have there been cases where changes to default preference values are only effective in new profiles? Or to put that another way, are there cases where existing profiles are customized during an update to preserve old default preference values? The currently effective default value of a non-customized preference isn't written to the prefs.js file; it is inherited from the program files. So preserving an old default would seem to involve checking whether the user has customized the preference and, if not, manually creating a custom preference set to the old default, and then manually recording that this has been done so it doesn't get repeated at every update (otherwise, the user would not be able to switch to the new default).
This change affected my existing profile. Over two weeks of frustration before searches finally brought me to this thread.
Considering that this makes the action of a scrolling with a modifier key the same as scrolling without it, I'm not sure that this is helpful unless this was known to cause significant confusion for new users.
I am nonetheless grateful that the option to change the behavior remains.
It was super hard to find that 1) this change happened (I thought I was going crazy!) 2) how to change it back (What an absolutely arcane way to revert back to old functionality).
If you are gonna change behavior in a breaking way, at least offer a better way to teach people who to revert to the way they liked it.
This change has been extremely frustrating for me, I thought I was going crazy until I stumbled over this post.
Terrible choice to change the Firefox default behavior in this case in my opinion, at the very least this should be in the actual settings, not hidden in about:config. And just to be clear, this is a terrible on Apple's part too.