Molten Vault Map not spawning abysses in "Overrun" map Ref# 3,946,057,367

Area overrun by abyss in "Molten Vault" map is not working properly, there was only a SINGLE abyss node and 33 monsters total in the map (the league mechanic + the one abyss + the map boss)

Reference number 3,946,057,367

my maps mods were as follows:
19% Exp Gained
46% more gold found in area
60% more monster life
Monsters deal 39% of Damage as Extra Cold
Abysses spawn 56% increased monsters
5 Additional rare monsters are spawned from abysses
Area contains 17 additional abysses
Area is overrun by the Abyssal
area has 48% chance to contain four additional abysses
Monsters have 14% increased attack and cast speed
monsters have 28% chance to inflict bleeding on hit
area contains 4 additional abysses
rare monsters have 1 additional modifier
area has 116% increased chance to contain shrines
4% increased quantity of items
104% increased rarity of items
118% increased magic pack size
141% increased number of rare monsters
162% increased waystones found in area

This isn't the first time I've encountered this with Molten Vault specifically, but the first time I've decided to document it.