HoMM3 HD bug reports.

To obtain clear evidence, the same battle needs to be conducted in three variations: without HD, with HD, and with HD+. After that, it will become clear whether this is due to HD or something else.

The fact that the AI attacks a wall of fire placed close to its own units with two-hex units has been known for some time and has been demonstrated repeatedly, including on my stream. This occurred in the following situations: 1) If there are not just single units behind the wall, but many units, some of which will die after the attack, especially if there are ranged units there. 2) If the single unit is not placed in the center of the right edge of the field, but at the top or bottom. In this case, part of the two-hex units attack, and part do not, in this way. It is difficult to say what this is related to, but I have noticed that this is true when one of the parts of the wall (top or bottom) is adjacent to the edge of the field or another obstacle.