What you see is not what you get. When a batch has finished and moves on to the next, and you close and reopen the combat armory, it skips back to the previous batch. Don't know if it has anything to do with an active buff, neither do I know if it's just a graphical glitch.
Also the progress bar sometimes freezes.
When you try to add a batch in the combat academy while the previous batch finishes a unit, your current batch is cancelled.
Just tested the combat armory bug: It is not just graphical. It actually increases production time. Also it's not the buff.