I am trying to install in-line presser foot set onto my CB4500. I installed the needle foot and the back presser foot okay. The back presser foot position was fine, but I needed to lower the needle foot a little. I loosened the nut to adjust the needle foot. While making this adjustment I heard a clunk, I think the back presser foot dropped a little, and it no longer walks (goes up and down). I am very much a novice so if you think you can help, please pitch your answer accordingly :). I attach a video. I took the face plate off for the video; I assume it’s something in there that needs attention.
if the video isn’t accessible, I’m attaching a photo that may help. TIA.