Breach monster spawned in terrain and broke the encounter

Did an unstable breach encounter in shipyard map, and one of the 4 rares that spawn on stabilising it is stuck in terrain. Can't damage it, it won't move, encounter is impossible to finish.

Was a memory chain map at eagon, but I'm pretty sure it's just the terrain of the map that caused it. One of the stacked slab looking things that exist in that map.

On PS5Pro