MacOS has built-in keyboard navigation across all applications (see here for an overview). The shortcuts involving option (⌥) have stopped working in Obsidian.
For example, ctrl-option-f and ctrl-option-b move forward and back a word, respectively, and option-d forward-deletes one word. I use these all the time in Obsidian, but they stopped working today (Does Obsidian auto-update?).
we never had ctrl-option-f and ctrl-option-b. We had option-f, option-b, option-d emacsy style shortcuts. They have been removed because they interfere with what is the current default in mac os.
You can file a feature request or plugin request to add ctrl-option-f and ctrl-option-b.
I wouldn’t request adding these shortcuts in specifically. I wonder more about what Obsidian is doing differently from all other apps, where these shortcuts work without any app-specific code written for them – as these shortcuts are built into MacOS itself, like how I’m using them to write this very comment.