RMChess1954 wrote:
https://www.chess.com/explorer?moveList=d4+g6+c4+Bg7+Nc3+d6+e4+Nc6+Be3+e5+d5+Nd4&ply=12
The second option I think it's dxe6 is a glitch. Impossible move.
Pretty sure it is due to the fact the database is only aware of position, not move order. So, it sees the position could have been reached in a transposition were d5 was the last move
Any position where there is a transposition like that, in particular where an en passant capture is potential in the position but not in the move order will have that problem.
The site apparently isn't setting the FEN correctly when going through the moves or just isn't using the full FEN when matching positions. I've seen other topics about it in the past.
https://www.chess.com/explorer?moveList=d4+g6+c4+Bg7+Nc3+d6+e4+Nc6+Be3+e5+d5+Nd4&ply=12
The second option I think it's dxe6 is a glitch. Impossible move.