I dont believe it appears to be dieing. Soft corals often "shed" their skin as they grow or need to remove crap on thier tissue...like other coral chemicals.
if i were you, i would move it from that acan. But otherwise, i think it looks good to be honest.
keep an eye on it and be prepared to remove it and treat.....soft corals have a way of diminishing very quickly if something is wrong.
beautiful acan BTW, and leather for that matter.