This function is itself without bugs

But I found that the search (number of visited nodes in Alpha_Beta, and score for an iteration) is not symmetric if the color to play and the position are reversed. When I use a simple material eval then only the number of visited nodes are just slightly differents. My full eval seems without bugs as far as i know, though it is very complex and may still have some (without bugs=symmetrical for both sides of course).
I have no null move and no transposition tables.
Trying to understand that I played with LMR and found that avoiding to reduce tactical moves reduced the difference of search between a position and the symmetrized position (ok it is good to do that but why could it cause such large effects).
As far as I understand doing the modification above on LMR tends to reduce the difference of search between a position and a symmetrized one.
Before to come to the conclusion, please look at an example on this
initial position :
1k1b3r/ppp3p1/3p1p2/3Pr2q/P2N3p/5Q1P/1PP2PP1/1K1R3R w - - 40
[diag]1k1b3r/ppp3p1/3p1p2/3Pr2q/P2N3p/5Q1P/1PP2PP1/1K1R3R w - - 40[/diag]
it is a well known position given by kostyev and the solution is
Nc6+
Here is the result of Milady search when allowing captures in LMR
(allowing to reduce captures) :
"depth 1 score -23 temps 1 nbnod 47 B_F :46 : f3h5 : Alpha futur -20000 , Beta futur 20000"
"depth 2 score -23 temps 3 nbnod 314 B_F :16,3401346383682 : f3h5 h8h5 : Alpha futur -20000 , Beta futur 20000"
"depth 3 score -16 temps 12 nbnod 1944 B_F :11,7687192189956 : f3h5 h8h5 c2c4 : Alpha futur -20000 , Beta futur 20000"
"depth 4 score 15 temps 27 nbnod 4566 B_F :7,15579963791388 : f3h5 e5h5 d4e6 g7g6 : Alpha futur -20000 , Beta futur 20000"
"depth 5 score -19 temps 91 nbnod 16320 B_F :6,51684118319441 : f3h5 h8h5 c2c4 e5e8 f2f4 : Alpha futur -20000 , Beta futur 20000"
"depth 6 score 16 temps 229 nbnod 39932 B_F :5,35618368662256 : f3h5 e5h5 d4e6 h5f5 f2f4 d8e7 : Alpha futur -20000 , Beta futur 20000"
"depth 7 score 5 temps 531 nbnod 103746 B_F :4,85754202804267 : f3h5 e5h5 d4e6 h5f5 f2f4 d8e7 b1a2 : Alpha futur -20000 , Beta futur 20000"
"depth 8 score 28 temps 1157 nbnod 213429 B_F :4,26596624848348 : f3h5 e5h5 d4e6 h5f5 f2f4 g7g6 h1e1 h8e8 : Alpha futur -20000 , Beta futur 20000"
"depth 9 score 198 temps 4132 nbnod 809431 B_F :4,38222014318091 : d4c6 b8a8 c6e5 f6e5 f3e4 a8b8 d1d3 h5f7 f2f3 : Alpha futur -20000 , Beta futur 20000"
"Test_Stabilité 28: f3h5 198: d4c6"
"Stab = False"
"depth 10 score 194 temps 14752 nbnod 2407956 B_F :4,17226556277527 : d4c6 b8a8 c6e5 f6e5 f3e4 d8g5 f2f3 h8b8 e4f5 c7c5 : Alpha futur -20000 , Beta futur 20000"
Below is the result if I don't allow captures to be reduced:
"depth 1 score -23 temps 1 nbnod 47 B_F :46 : f3h5 : Alpha futur -20000 , Beta futur 20000"
"depth 2 score -23 temps 3 nbnod 314 B_F :16,3401346383682 : f3h5 h8h5 : Alpha futur -20000 , Beta futur 20000"
"depth 3 score -16 temps 12 nbnod 1940 B_F :11,7590845694012 : f3h5 h8h5 c2c4 : Alpha futur -20000 , Beta futur 20000"
"depth 4 score 15 temps 29 nbnod 4650 B_F :7,21509946842602 : f3h5 e5h5 d4e6 g7g6 : Alpha futur -20000 , Beta futur 20000"
"depth 5 score -19 temps 98 nbnod 17130 B_F :6,59542698873255 : f3h5 h8h5 c2c4 e5e8 f2f4 : Alpha futur -20000 , Beta futur 20000"
"depth 6 score 16 temps 243 nbnod 42339 B_F :5,41492696105803 : f3h5 e5h5 d4e6 h5f5 f2f4 d8e7 : Alpha futur -20000 , Beta futur 20000"
"depth 7 score 5 temps 553 nbnod 110533 B_F :4,90382729325774 : f3h5 e5h5 d4e6 h5f5 f2f4 d8e7 b1a2 : Alpha futur -20000 , Beta futur 20000"
"depth 8 score 28 temps 1531 nbnod 267340 B_F :4,46088143911947 : f3h5 e5h5 d4e6 h5f5 f2f4 g7g6 h1e1 h8e8 : Alpha futur -20000 , Beta futur 20000"
"depth 9 score 195 temps 5685 nbnod 1110013 B_F :4,55414196182894 : d4c6 b8a8 c6e5 f6e5 f3h5 h8h5 h1e1 h5f5 f2f3 : Alpha futur -20000 , Beta futur 20000"
"Test_Stabilité 28: f3h5 195: d4c6"
"Stab = False"
"depth 10 score 206 temps 13291 nbnod 2342889 B_F :4,06529382043233 : d4c6 b8a8 c6e5 f6e5 h1e1 h5g5 e1e3 h8e8 e3b3 c7c5 : Alpha futur -20000 , Beta futur 20000"
Now the reverse position :
1k1r3r/1pp2pp1/5q1p/p2n3P/3pR2Q/3P1P2/PPP3P1/1K1B3R b - - 40
[diag]1k1r3r/1pp2pp1/5q1p/p2n3P/3pR2Q/3P1P2/PPP3P1/1K1B3R b - - 40[/diag]
For this reverse position; the analysis of Milady when LMR allow
captures
"depth 1 score 0 temps 1 nbnod 46 B_F :45 : f6h4 : Alpha futur -20000 , Beta futur 20000"
"depth 2 score -23 temps 3 nbnod 221 B_F :13,228756555323 : f6h4 h1h4 : Alpha futur -20000 , Beta futur 20000"
"depth 3 score -16 temps 9 nbnod 1326 B_F :10,3384181241454 : f6h4 h1h4 c7c5 : Alpha futur -20000 , Beta futur 20000"
"depth 4 score 15 temps 21 nbnod 3386 B_F :6,73700399819095 : f6h4 e4h4 d5e3 g2g3 : Alpha futur -20000 , Beta futur 20000"
"depth 5 score 9 temps 70 nbnod 13004 B_F :6,26061438188652 : f6h4 e4h4 d5e3 h4f4 e3d1 : Alpha futur -20000 , Beta futur 20000"
"depth 6 score 15 temps 152 nbnod 26118 B_F :4,85611761235252 : f6h4 e4h4 d5e3 g2g3 e3d1 h1d1 : Alpha futur -20000 , Beta futur 20000"
"depth 7 score 5 temps 442 nbnod 87191 B_F :4,82717174234912 : f6h4 e4h4 d5e3 h4f4 f7f5 d1e2 b8a7 : Alpha futur -20000 , Beta futur 20000"
"depth 8 score 16 temps 1035 nbnod 193754 B_F :4,25060554862605 : f6h4 e4h4 d5e3 h4f4 f7f6 g2g3 e3d1 h1d1 : Alpha futur -20000 , Beta futur 20000"
"depth 9 score 9 temps 2892 nbnod 592517 B_F :4,19084550114119 : f6h4 e4h4 d5e3 h4e4 e3g2 e4g4 g2e3 g4g7 f7f6 : Alpha futur -20000 , Beta futur 20000"
"depth 10 score 25 temps 7333 nbnod 1368591 B_F :3,88141708692493 : f6h4 e4h4 d5e3 h4e4 h8e8 g2g3 e3f5 e4e8 d8e8 g3g4 : Alpha futur -20000 , Beta futur 20000"
The good move is not found even at depth 10 !
But when the captures are not reduced by LMR :
"depth 1 score 0 temps 1 nbnod 46 B_F :45 : f6h4 : Alpha futur -20000 , Beta futur 20000"
"depth 2 score -23 temps 3 nbnod 221 B_F :13,228756555323 : f6h4 h1h4 : Alpha futur -20000 , Beta futur 20000"
"depth 3 score -16 temps 9 nbnod 1357 B_F :10,4342068925523 : f6h4 h1h4 c7c5 : Alpha futur -20000 , Beta futur 20000"
"depth 4 score 15 temps 21 nbnod 3495 B_F :6,79989059373661 : f6h4 e4h4 d5e3 g2g3 : Alpha futur -20000 , Beta futur 20000"
"depth 5 score 9 temps 74 nbnod 13880 B_F :6,35742580171929 : f6h4 e4h4 d5e3 h4f4 e3d1 : Alpha futur -20000 , Beta futur 20000"
"depth 6 score 15 temps 156 nbnod 28719 B_F :4,95717334500454 : f6h4 e4h4 d5e3 g2g3 e3d1 h1d1 : Alpha futur -20000 , Beta futur 20000"
"depth 7 score 12 temps 517 nbnod 103560 B_F :4,96941943948923 : f6h4 e4h4 d5e3 h4f4 f7f5 d1e2 c7c5 : Alpha futur -20000 , Beta futur 20000"
"depth 8 score 16 temps 1301 nbnod 242808 B_F :4,39514918307835 : f6h4 e4h4 d5e3 h4f4 f7f6 g2g3 e3d1 h1d1 : Alpha futur -20000 , Beta futur 20000"
"depth 9 score 187 temps 5303 nbnod 1071272 B_F :4,54554498535173 : d5c3 b1c1 c3e4 f3e4 f6g5 h4g5 h6g5 d1g4 h8h6 : Alpha futur -20000 , Beta futur 20000"
"Test_Stabilité 16: f6h4 187: d5c3"
"Stab = False"
"depth 10 score 191 temps 12083 nbnod 2164080 B_F :4,01656118063693 : d5c3 b1c1 c3e4 f3e4 f6g5 h4g5 h6g5 d1g4 h8e8 h5h6 : Alpha futur -20000 , Beta futur 20000"
this search result is much more consistent with the one of the symmetrized position.
Now i come with the conclusions, and i would be very glad to have
your advice

in the past, please give me your advice. Also, is it normal that
a search may be unsymmetric?
Sorry for that long description,
Yves