While playing Exchange map #834, I encountered this. No unulusal play, just laying down Omnis as per usual. Those bugged were the first to be laid. Omni reactor tech is at 28% at time of screenshot.
Running the current beta (V1.16, I think?).
Loading the mission and those two unbuilt omnis complete. The others are full energy and everything remains at full energy after that without packets because of the tech. Could be an edge case where the tech was coming up to speed and the omni wasn't complete yet and the calculation was off by one. But a building omni doesn't use the omni reactor tech, so that shouldn't be the case. Strange...
I've seen this bug as well.
I've also restarted without 'Omni Reactor' and I still saw it.
The omni's only needed another packet to complete, I guess somehow the game decided they were full.
This bug occurs even with ships on this map sometimes. My solution for it is to setup your defense at gamestart while pause is on, and then I saved the game. After that i unpause and let the game flow. If any bug happens I just reloaded and everything is going fine.