Problem: After winning a battle, a CPU army stops near the enemy base, just out of sight, and, instead of taking a few paces forward and attack, turns back to its own site, giving the enemy an opportunity to recover.
Comment: Apparently no bug here: if the base is out of seeing distance, it seems logical to make it depend on chance that the attacking army discovers it. The problem is that in many such cases the base had already been discovered by previous fighting units. To profane eyes, it looks strange to see that the AI has entirely forgotten the location.
Suggestion: Make a previously explored enemy base a permanent objective for the CPU faction. It should be easy to store the coordinates, although not so easy, perhaps, to decide what to do with them. But common sense dictates that an army of a substantial strength should always attack the nearest base without hesitation.