Nudge +1 or -1 frame is now seemingly unhinged from where I drop my cursor. I place my cursor on the exact subframe of a whole frame and nudge by +1 frame and it only moves 2/3 of the way. Not to the next ‘whole’ frame. Is there a setting I am missing?

Preferences: show subframes + Snap to grid + zoom resolution ?
Would that do it ??