Yes, I also have the same icon marked on my map showing where Enigma's hideout is saying the same thing. I have completed all data packs relay's and finished singleplayer mode 100%. I went into the secert room and got the secert item too. I just want it off my map cause its the only thing left lol. Are you playing on the PC aswell?
I am having the same problem and I am playing on PC.