Abyss is not spawning any more in maps.

I had bug in act 2 valley of titans where I was not able to complete abyss. So I left it as it is. But now I am in utzaal in act 3 and in between all zones abyss never spawned for me.

Thanks

Update : Looks like abyss is end game mechanic. Abyss showing up in valley of titans it self is bug.