Just played an auto-game and was looking through history and found something surprising on turn 3: https://war.app/MultiPlayer?GameID=19509917. My opponent only deployed 5 when he had an income of 12. How could this have happened? Is this a bug?
That's auto-commit. If you reach the boot time, instead of booting you the server will just use whatever orders you've entered so far, even if they don't fully deploy all armies.
To avoid this happening, be sure to commit your orders before the timer hits 0.