What is the fifth position in the KN vs. KR endgame with the knight mating? I can come up with 8 positions where the knight would deliver checkmate to a rook and king. However, on endgame tablebases, there are only 5 positions where a King knight wins against King rook. Why?
The positions are not unique if they are in some way symmetrical.
The five positions where KN wins vs. KR are:

White to play:  White Kc1 Nd2, Black Ka1 Ra2
White to play:  White Kc1 Nd4, Black Ka1 Ra2
White to play:  White Kc1 Nc5, Black Ka1 Ra2
White to play:  White Kc1 Na5, Black Ka1 Ra2
Finished game:  White Kc1 Nb3, Black Ka1 Ra2