Why stockfish can`t find the best move if we have one line to analyse but if we have two lines it can find the best in some positions for example 8/8/N1p1P1p1/3p3p/8/b1kP4/P7/7K w - - 0 4 (Cb4!) 1B3N2/3K1p1B/5pn1/5krb/2P1p1p1/4P1P1/4PP2/8 w - - 0 17 (Ce6!)