Sorry, I thought you were at 86F. If their gills are beating normally, keep increasing temp. Try and get temp up at a decent pace as most cases require 86F to be effective. It's a tricky one - try to increase as fast as you can per guides in links above without having fish lost. When I've jacked the temp up I've seen rapid gill movement for the first night or so.
Is this a planted tank? Also what was fish stocking again?
"Only" a few fish lost suggests a combination of stress from infection, meds, etc too much for them. It happens unfortunately. I've treated with malachite green / formalin and promptly lost all my uninfected bn catfish (only some mollies had it badly) - where I did put it down to my dose rate / young, scaleless fish.
Is this a planted tank? Also what was fish stocking again?
"Only" a few fish lost suggests a combination of stress from infection, meds, etc too much for them. It happens unfortunately. I've treated with malachite green / formalin and promptly lost all my uninfected bn catfish (only some mollies had it badly) - where I did put it down to my dose rate / young, scaleless fish.