Ennemy stuck in ground, untargetable and unkillable

During a map, a rare monster is stuck in the ground and renderered unkillable, even though it stills attacks me. He still appears in the minimap and is moving, preventing the completion of the map (only rare monster left in the map).

https://streamable.com/r0vht4

Bug report reference number : 1778696384

I happened to me too on a Vall factory map