Abyss not fully spawned on Bog 3.25

Bug report ref number: 625,093,881

I used
2x Abyss scarab
2x Abyss scarab of multitudes
1x Scarab of monstrous lineage

Tier 16 Bog, map modifier says
Area contains 4 additional abysses, but only one was spawned.
Clear all map and boss area.