TLDR: Keyframes get changed by other keyframes
I got an animation rig with some IK and bone parenting so both hands stay on the weapon. I have to correct the hand position on different frames because the location/rotation is not 100% correct. However after correction the location/rotation of another keyframe the other keyframes also change?! How is that possible when keyframing all bones? What do i have to do so keyframe 0 (and all other keyframes) are not affected by changing other keyframes? Here some pictures: Pose at keyframe 0:
Pose at keyframe 4 (without correction):
After correcting the pose on keyframe 4:
Here is a short video where i replicate the problem and explain the behavior i want from blender: https://youtu.be/AHzZIUuj69M
Please let me know if you need something else!