When the enemy ship’s hull is at 90%, the Destroyer activates 2 gravity anomalies or generators.
There is one problem with those 2 generators.
Some ship’s modules cannot deal any damage to them.
Known issues with specific ship’s modules:
Pyro Emitter Module (Destroyer)
Gravi-Lens Module (Destroyer)
there could be more module related abilities that do not deal any damage
Logs: (look to my previous bug report and use those logs)