I figured out what was causing the issue, although not the exact mechanism behind it. I was using your tutorial as a reference for walk cycles, but not your specific rig. The rig I was using was based upon rigify, but it was heavily modified. many of the control bones had bone constraints added to limit movement to try to prevent the rig from breaking the model, and they were causing the odd behavior of the keyframes changing after keying. I am hypothesizing that this is because of the order of operations, and that the constraints were being applied after the action of keying. I am not sure if this is the specific cause, and I don’t know how to test it, but the issue is gone without the bone constraints, so my solution is to remove the constraints, and just be careful when keying to not break the model. This issue is specific to the rig, so, sorry about not specifying that I was using a different model, I just got extremely frustrated after spending hours trying to determine the cause of the odd behavior.
