Don't know how widespread this bug is, but currently I cannot progress in my Chaos Campaign because the Phalanx is sitting in the Agrippina system (need it for resources).
-Phalanx is in Agripinaa Sector
-Use Slaanesh gift to move the 3 fleets guarding the system to somewhere else, so when battle does begin it is just the Phalanx and some turrets
So I had run into the Phalanx before and knew that at 1/3 health, it disengages out, so I took a setup to basically counter this
I have two World Eater fleets, and my ship composition for the battle are 4 of the new ?Hecarte? ships (the battlecruiser class with two launch bays).
-I have both ships kitted out basically for maximum boarding-helldrake forges, etc.
Battle begins and it is one of the "transporter" secondary objectives- all the transport ships promptly ram straight into the phalanx and die.
Then through a combination of boarding pods, regular boarding, and the World Eater special I can get it up to a ridiculously high boarding stack (Like 50 to 60 boarding stacks)
This makes the Phalanx spend the entire battle in the "Call to Arms" stance, making it easy prey to be picked apart, and I go back into boarding range to refresh stacks.
Then, at 1/3 health, it tries to disengage out; but it still has like 40 boarding stacks. Normally, this would just cancel the disengage attempt.
However, instead, the Phalanx stops taking troop damage, the disengage bar reaches full, and then the disengage bar just stays there at full for a little bit (like 2 minutes or so?). The disengage bar then disappears, but the phalanx is no longer taking troop damage.
Edit: Also, while "disengaging", the Phalanx still moves around and shoots at my ships.
Finally, I reduce the Phalanx to 1 HP, at which point it becomes invincible/doesn't die- I can't kill it because it stays at 1 HP, can't turn it into a drifting hulk because it doesn't take any troop damage, ramming it while it is at 1 HP also does not work. The mission was also annihilate so I cannot just VP out-cap the AI.
Don't know if this is a duplicate post or if anyone else has encountered this bug, but it is pretty much campaign breaking because I cannot retreat, and will otherwise lose two fully-kitted out World Eater fleets.