Nudge Feature/ Keyboard Shortcut Not Working In Timeline

I went to go nudge an audio clip in the timeline by one frame using alt+left/right yesterday (like I always do) and it is no longer working. The keyboard shortcut for nudging a clip by five frames left and right still works, and nudging up and down still works, but not nudging one frame left or one frame right. I’ve tried uninstalling and reinstalling premiere, resetting the original settings, etc. and nothing works. How can I fix this?