Tab over dialog box options

I have always used the Tab key to move across dialog box options, but this doesn't work, at least not universally within Apple or 3rd party apps. So as far as I can tell, I must now use the mouse.

For example, open the Mail app, create a new email, and then close the window. A dialog box opens with the "Save," "Don't Save," and "Cancel" options. Initially, "Save" is highlighted in blue. In the past, I could use the Tab key on my keyboard to move the highlight from "Save" to "Don't Save" to "Cancel." Now, I can no longer do this using the Tab key.

If you open a TextEdit file, type something, then try to close, you can move from the "Save As" and "Tags" fields using the Tab key, but I cannot access the "Delete," "Cancel," or "Save" buttons in the dialog box using the Tab key.

In the past, I used the Tab to navigate these dialog boxes in all apps, Apple and otherwise. I'm a power user who prefers to keep my hands over the keyboard as much as possible, so having to use the mouse is a nuisance.

Can someone tell me if there is a preference I can change or whether this is a fixed preference in Big Sur?

Big Sur 11.6

2020 MBP 13in