I don't think this is technically a bug, since nothing actually failed to work. But while I was playing, with Regulus as an AI player, he had some... interesting choices of locations to place mines. I think the strangest was when he placed one under/next to an enemy tower of light. It detonated imediately, which sort of defeats the purpose, and from an AI perspective, probably wastn't the most efficient use of time or energy. I also saw him going through mine-laying animations right over existing mines. I'm not sure if this was placing a second in the same spot, or a true bug, but afterwards, it looked like enemy units could run over that location without detonating one or both of the mines (as in, there was still at least one graphic left.)