Cross-planet attacks syncing up with exogalactic strikes

[Executor]

What determines whether this occurs? I thought the only condition was if the exo had progressed to at least 60%. In a recent 9/9 difficulty game, that's what I experienced. But now I'm playing on 10/10 and it's no longer happening. I even reloaded to before the CPA being announced just to double-check; still nothing. Is it bugged? I would've jacked up the exo plot intensity to 6/10 if I had known this would happen.

Some screenshots, with game settings:

[Faulty Logic]

I thought the only condition was if the exo had progressed to at least 60%.

The other condition is game time must be past five hours.

I'm guessing the difficulty nine AI's first exos were past that point.