Delete previous key assignments on midi keyboard

I recently started using a midi keyboard instead of a computer keyboard for note input. I programmed some of the keyboard notes (C, C#, D, D#) to correspond with note values. I want to un-do that because there are other buttons on the midi keyboard that can be assigned to note values. Now when I try to play those notes, they won't play because they've been assigned to something else. I've reprogrammed the note values to other buttons on the midi keyboard, but unfortunately, that didn't take off my original programming. I've tried resetting back to default in the Note Input preferences but that doesn't reverse my original assignment of those keys.

I would appreciate any direction on how to program those notes back to notes (and not note values). I am using MuseScore 3.

Thanks very much.