Yes, I created this thread: AI Cheating on Single Player Maps. Over the past few years, I've collected 6 save files demonstrating this outrage, and I've encountered it on even more maps, but then I didn't feel like saving anymore because the symptoms are the same: movement on the map is impossible, but the AI flies. I don't know anything about the origin of this bug, but it sometimes manifests when an AI hero really wants to get somewhere. And another 2-3 times I observed that it starts with completely legitimate walking on water, but then turns into flying. Perhaps this is a mistake or oversight in the code where they simply forgot to add an additional check. So far, there is no way to deal with this; you can only defeat the flying hero.
Is this phenomenon described anywhere in Physigma? Have you tried reporting this to the programmers? Baratortchu, Savu, or someone else?