DOUBT on INACURACY

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e5 5. Nb5 d6 6. N1c3 a6 7. Na3 Be6 8. Nc4 Rb8 9. a4 Nf6 10. Bg5 Nd4 11. Bd3 Be7 12. O-O O-O 13. Bxf6 Bxf6 14. Nd5 Bg5 15. c3 Nc6 16. Ncb6 g6 17. b4 Kh8 18. a5 Bh6 19. Ra3 f5 20. exf5 gxf5 21. Qh5 Bg7 22. Bb1 e4 23. f3 exf3 24. Rxf3 Qe8 25. Qh3 Ne5 26. Rf1 Ng4 27. Qd3 Qh5 28. h3 Ne5 29. Qc2 Bh6 30. c4 Rf7 31. c5 dxc5 32. Qxc5 Nc6 33. Raf3 Bg7 34. Kh1 Bd4 35. Qd6 Bxd5 36. Nxd5 Rd8 37. Qe6 Qg6 38. Bxf5 Qxe6 39. Bxe6 Rxf3 40. Rxf3 Be5 41. g4 Nd4 42. Re3 Bd6 43. Re4 Nf3 44. Rc4 Ne5 45. Rc8 Rxc8 46. Bxc8 Nc6 47. Bxb7 Nxb4 48. Ne3 Bc5 49. Nc4 Kg7 50. Kg2 Kf6 51. Kf3 h5 52. Kf4 Nd3+ 53. Kg3 hxg4 54. hxg4 Nb4 55. Kf4 Nd3+ 56. Ke4 Nb4 57. Ne5 Kg5 58. Bc8 Be7 59. Bd7 Bf6 60. Nf3+ Kg6 61. Be8+ Kg7 62. Nd4 Kh6 63. Ne6 Nc2 64. Kf5 Bc3 65. g5+ Kh7 66. g6+ Kh6 67. Ke4 Nb4 68. Nd4 Kg7 69. Nf5+ Kf8 70. Bd7 Bf6 71. Ba4 Na2 72. Bc6 Nb4 73. Bb7 Bc3 74. Ke3 Bf6 75. Kd2 Be5 76. g7+ Kg8 77. Bc8 Bxg7 78. Nxg7 Kxg7 79. Bb7 Kf6 80. Kc3 Na2+ 81. Kc4 Ke7 82. Bxa6 Kd6 83. Bb5 Kc7 84. Kb3 Nc1+ 85. Kb2 Kc8 86. Ka3 Kb8 0-1 Move number 31. I know first inaccuracy backward pawn is weakness. I cannot understand next three inaccuracies (move 31 to 32).

Move 31 correctly identifies the d6 pawn as a weakness since it looks backwards (although more accurately it is isolated and blockaded by the d5 knight), but c5 was a mistake because it gives black the chance to trade away their weak pawn.

Move 32 was an inaccuracy according to the quick analysis probably because Nf4 was the slightly better move, but 32. Qxc5 was fine in my opinion too. Nf4 forks the queen and e6 bishop, so it provokes black into playing ...Bxf4 and this makes black give up the "bishop pair" which is often evaluated at roughly half a pawn of material.

Move 33 was innaccurate for the same Nf4 move being considered slightly better by the post-game analysis for the same reason.