i found a bug for 3.4.1 free version. you chose black, and machine picks white. the last move below, white eats black pawn wrong.

1. e2-e4 e7-e5 2. Ng1-f3 Bf8-d6 3. Nb1-c3 Ng8-f6 4. Bf1-b5 O-O 5. O-O c7-c6 6.
Bb5-e2 Nf6-g4 7. Nf3-e1 Ng4xh2 8. Kg1xh2 Qd8-h4 9. Kh2-g1 f7-f5 10. Ne1-f3
Qh4-h6 11. Be2-c4 Kg8-h8 12. d2-d4 Qh6-f6 13. e4xf5 Qf6xf5 14. Bc4-d3 Qf5-f7 15.
Nf3xe5 Bd6xe5 16. d4xe5 Qf7-e6 17. Qd1-h5 g7-g6 18. Qh5-h6 Qe6-e7 19. Bc1-g5
Qe7-f7 20. Qh6xf8 Qf7xf8 21. Bg5-f6 Kh8-g8 22. Bd3-c4 d7-d5 23. e5xd6 $0 *