I just did a zakum run with 2 other shadowers and at least 1 other was having this issue. For some reason, smoke screen doesn't work for everyone in the cloud, including the one who cast it. There was one case where the crossbowman in our party was able to bypass damage while in it but me and one other shadower still took damage/skill effects. It was working fine a few weeks ago for me. This bug also happened when I was fighting Anego so it isn't a zakum specific bug. The only thing I did before I noticed the bug was check out the toad boss. For some reason, smokescreen was able to protect me from some of the spikes. (I'm not sure if this is a bug) Maybe that might be what caused it to have problems? Either way, it is broken for me now so I'm hoping there is a way to fix it. (I have tried re-logging)