So I have noticed this problem happening a couple of times now. In a spawn with battleships like the Marshal or Overminds where the drones take a lot of damage the bot starts recalling and sending out the same damaged drones again and again making the timer run out without anything getting killed. Someone else posted the same problem in de feedback forum.

Slav I have send you a log file from when this happened the last time.

Yes that was me
thats good that you have sended the log. That was my fail.
I think if the Bot callback both he start the new Drones with Shortcut and the Game then start always the Drones that are one the Top of the List in Bay and these are the last ones.