My shortcut key for “Again” is not working. 1 did not work, so I tried to set 9 as the shortcut for “Again.” That did not work either.
When I hover my mouse over the “Again” button, it does show, “Shortcut: 1” or “Shortcut: 9.”
I have set my keyboard to English. I also restarted Anki many times (including restarting it while pressing “Shift” to disable any add-ons, in case they were causing the issue).
Interference from an add-on was going to be my first, so thank you for eliminating that already. (To clarify, you held Shift down until you saw the confirmation message that add-ons were disabled?)
Are you using the 1 in the number row of your keyboard or on the keypad?
What version are you using? Click Help > About > Copy debug info and paste the full result here.
Am I correct in assuming you’re making these answer button changes in Tools > Preferences?