How do I edit keyframes of an animation

Hi everyone,

As the title says I'm trying to edit an animation and adjust the rotation of the hand during a walking animation. Whenever I go to add a key frame with a change to the characters hand, it disappears completely. I'm noticing that if I try to edit the parent object it works fine but I'm scratching my head when I'm trying to rotate the hand. Please see the following images of my hierarchy and animation tab.

The red outline represents what is working while editing key frames and yellow represents what I am trying to edit and save.