[Bug] during Companion quest "Things Lost, Things Found" (may be tied to despawn bug)

Casdha

While I was doing my companion Quest with Bastain I would get a start quest marker above every Mirri (tied to other players) I ran into. I have not started playing with Mirri yet. The first time I tried to interact with Mirri I got part of a line and she disappeared before I could read it, after that I could no longer interact with them as I saw them. I took a screen shot with one of them in Ilessan Tower.

Edit: may be tied to the despawn bug I read from others.