They want bright filtered light not full sun.

It is from one of two things, too much water or too little. I suspect it's too little, as you have other vines doing well. Perhaps the sickly fine is rooted to close to the surface of the plant. But you can get an affirmative answer by removing the plant from the pot and checking the roots. If they look healthy, it's probably underwatering. If there are rotten slimy brittle roots it's overwatering. While you have the plant out, I would see if I could get an unhealthy vine out and inspect it's roots individually, looking for the same symptoms. Good luck.