Allmighty Cube II Not spawning

[BaconCake28]

I was just playing through the campaign as normal when the Allmighty Cube 2 suddenly despawned. I was able to fight it once, lost and went off to get some new weapons first. But when I came back it was gone.
The markers on the mini-map are still there, and the quest marker is still there but nothing is spawned in the world.

I've been looking around and I've found reports of this in late 2020/early 2021 but nothing since and nothing about a fix.