This is quite an old bug but lately its causing skills to not fire. Not sure if its latency (NZ Player) but this has become more of a common thing as of late.
Using the training dummy i am constantly being bombarded with target is immune and skills like whip suddenly greying out. It is recently been happening in dungeons along with the target is out of range when i'm standing in front of them 1-3meters.
My guess is it has something to do with hit boxes but i really don't know tbh. It needs to be looked into as its a long time bug and it seems to be getting worse. Skills suddenly not firing because its immune to my spamable is not chill guys.