This is where our remote treatment of your fish is difficult. I'm looking over your pictures and it just struck me - you have like 2" of coral sand in the tank that you are dosing with copper! That opens up a whole slew of issues and questions: Calcium carbonate materials bind with copper medications to different levels, but it always something to be avoided. What test kit are you using to measure the current, active copper level?
This does still look like "stale ich", cases where ich has been on the fish for some time. As I said, there possibly could be a dual infection, but 100% you need to treat these fish with copper. Amine-based copper, like you are using aren't very harsh at all, but that means they also take more time to cure the fish....in some cases, they do not work fast enough to save all of the fish if the copper wasn't started soon enough.
You also need to ensure you are managing the water quality very well. The water looks very hazy to me (could just be an artifact of the photos) you need to have good mechanical filtration and then biological filtration sufficient to keep the ammonia level below 0.50 ppm. Do not add ammonia removing chemicals while dosing copper.
Jay
