Paste Opposite Shortcut Not Working Properly On Keyframes

Hello, so I’m currently on Lesson 55 (Making The Walk Cycle). At the end, it says to copy the keyframes, put the playhead on the last keyframe, and hit CTRL+SHIFT+V to copy the frames on the opposite side of the playhead. I did it but the right arm is not moving properly. What could be the problem? I swear I selected all the bones before pasting.

Here is the file:

Character19.blend (89.0 MB)

Also, something unrelated, there’s no mention of pole targets in this course unlike the A-Z course so I’m having trouble properly aligning the knee. Not sure how to align it properly like in the course since simply moving the foot bone in the X-axis doesn’t really fix it, as it does in the video.