Walkthroughs for custom maps.

The AI behaves very strangely in such situations; sometimes, it even starts going around the entire battlefield, even when there is a shorter path. In this example, the dragon can reach the destination in 9 turns; maybe tomorrow I'll try to recreate this situation again. I forgot to save after the battle, and I'll have to do something about it. :(

Based on my observations, in such situations, the computer stops moving through the quicksand when it has few units left in the stack; the stack simply stops. The second situation when they might stop is when the enemy has 7 stacks moving through the quicksand, and the most distant stacks see that their path is partially blocked, and then they also stop, for example, 3-4 stacks out of 7.
The computer goes "around" the shorter path because, it seems to me, it has already stepped on certain cells and "sees" an obstacle there, so it goes to the cells it hasn't stepped on yet.
A similar bug with stopping is especially noticeable during a siege of the computer in a castle, the destruction of its castle, and quicksand. In this regard, there are a couple of amusing moments: 1) you can lure the computer, a very large stack, into the castle moat, where it receives a small lesson and a defense penalty. If this is, for example, Crystal Legions, and we have 50 Archdevils, this greatly reduces the number of turns, and 2) there were 1-2 cases when, during such a siege, I killed all the computer's stacks, and it had summoned elementals left in 1 or 2 stacks, which "got stuck" in the moat, and I barely managed to pull back my forces before the computer died in the moat. :) After this, I learned to leave the computer with not the minimum forces in the last stack, but a reserve in case it gets stuck in the moat. :)