Oh sweet <3
Here it is
Thanks in advance!!
And there's your problem: One of the two AI types that was randomly chosen was a Scorched Earth type. That AI detonates a nuke, destroying the planet, whenever you destroy a command station belonging to that AI. The other AI does not do that, as you can see if you capture the Burnori system.
Unfortunately, it looks like your translation doesn't stick the "AI 1" "AI 2" labels into the name and you've chosen the same color for both AIs. This makes it difficult to tell the difference between the AIs, especially when trying to figure out differences like these.