Breach boss can spawn outside of mirage zone

In mirage the breach encounter spawned right next to the zone edge. When 2 bosses spawned 1 was inside and 1 was outside of the map. The one that was outside cannot be damage and it cannot move.

In-game bug reference number: 1 880 987 222



Edit:

Happened again, now with only 1 boss:

In-game bug reference number: 4 070 067 103

Can confirm have had multiple breach bosses spawn outside the mirage zone in dunes causing the breach to never close.