Not the 1st sector. It was dead loop, no fleet loss, domination raise to 100% after deploy then drop back to 0%.
Hmm, this looks more like a bug, but I haven’t been able to reproduce it in my tests yet.
If there are other hostile planets in the system, they may help the dominated planet to be reconquered. I don’t know if that was the case.
I’m finalizing some adjustments here. I’ll upload a new version with better balancing at the start of the game later today.