boss doesnt exist but does damage anyway

heyy, i am walking a T15 map but the last boss is not recognised by the game i think. in the screenshot you see on mini map where the boss is. it walks around like a corpse, dead on the ground,(the one on the stairs) but does shoot arrows and follows me and can actually hurt me. but if i hoover on the guy with my arrow, the name doesnt pop up, so i cant target him. and thus i cant finish the map :')

here i made a screen capture of the thing
https://cdn.discordapp.com/attachments/932774886286458940/1335662740471283733/boss-bug-T15-POE2.mp4?ex=67a0fc5c&is=679faadc&hm=9f64277defef072e54fac1cd735c6984a5747c5c5576511704afd1d0d3956131&