I had a wine that wouldn't clear no matter what I tried. Only thing that worked was cold stabilization. Basically put it in a fridge for as cold as it will get for as long as you need to clear it 3 days or more. After that it was crystal clear.
Another idea is super kleer. I have found that just the first part kieselsol, has cleared my whites flawlessly. For some reason the second part chitosan, has made my whites cloudy. I usually only add the chitosan if the kieselsol fails.
My wine was filtered and was crystal clear. Upon chilling, it clouded up. It may be a protein haze. I don't know yet if it worked for sure, but I added bentonite a few days ago at 2.5g/gal. I'll filter it again and bottle in a week or two.