Yep, that makes sense I think. Is the switch upstairs or downstairs?
I still think the problem is with the cable that's running between the patch panel and the RJ45 sovcket that you couldn't get good photos of. Try to get pictures of both ends of that cable, so the terminations into the RJ45 socket and on the patch panel.
I know you've tried already, but try new patch lead at both ends.