No no, you get me wrong, Stabbey. This was totally intended.
The small island in the middle of the 2 landmasses had a War Factory and my mouse was being wonky. So instead of attacking Imp Fighters on open sea I mistakenly let them attack that small island. I won via autoresolve. Next turn I thought "hey lets make a invasion force for the north islands from my newly aquirred island" and then noticed it was still red. I totally forget that you could only capture with ground forces.
Was kinda funny though. I just used my fleet to kill all ground forces and then move to the next. I targeted the war factory production zones first or as fast as possible. It made "hard" look like "casual".