I've been paying with this mod for a while now. 2nd play through, many hours (cant really guess) and I have not come across this. It might be helpful to list your mods so it can potentially be narrowed down.
It's not a mod issue. I've just now recreated it with just console commands and diable enabled. An ashfall, Two maelstroms and a pandemonium all bugged in the same battle. It's very easy to do so.
Start a new game with console commands to help. I'm assuming you are only using these two mods as well.
Skip the tutorial so you spawn at jangala which has a star fortress
open the console with ctrl+backspace
Turn on dev mode with "devmode"
Set your relationship to hegemony to max with "setrelation hegemony 100". This is so you can help them in the fight about to happen.
Then spawn a diable fleet with "spawnfleet diableavionics 300". It needs to be a high number so the capitals spawn, 300 should have 3-4 capitals.
Avoid the fleet so it engages the station, then engage the fleet while it is still fighting the station. Might help to reproduce if hegemony fleets join first, there should be some patrols nearby that will join.
In battle, open the console and use "reveal" to remove fog of war so you can look at the enemy ships easily. You can use the station's video feed or target an enemy ship and press T. You don't need to deploy anything yourself.
Watch any ship with the phase grazer system, if they use any weapons or the ship system, they didn't bug. Even while bugged, they can still deploy shield and spawn fighters.
If none of them bugged, press escape and choose end battle. This takes you back to the engagement dialogue and you can restart the fight. If it takes too many tries and the diable fleet's CR falls too low (4 or 5 engagements), use "nuke" to remove the fleet and try again with a new one.
While writing this I thought I might as well mention I am using java 23 during all this.