Illegal last move of PV.

[TheBlackPlague]

Occasionally, the last move of the PV line provided by StockNemo is illegal.

2022-09-14T03:35:25.591841155Z Warning: PV: Qe8+ Kf6 Qf8+ Ke6 Re3+ Kd7 Qe8+ Kd6 Qc6# d6d5
2022-09-14T03:35:26.557568712Z Warning: Illegal PV move c8b8 from StockNemo-050F4C13 (41)
2022-09-14T03:35:26.557654072Z Warning: PV: Kd6 Rd3+ Ke6 Re3+ Kd7 Qd5+ Kc8 Re8# c8b8
2022-09-14T03:35:26.557666225Z Warning: Illegal PV move c8b8 from StockNemo-050F4C13 (41)
2022-09-14T03:35:26.557675943Z Warning: PV: Kd6 Rd3+ Ke6 Re3+ Kd7 Qd5+ Kc8 Re8# c8b8
2022-09-14T03:35:26.557691112Z Warning: Illegal PV move c8b8 from StockNemo-050F4C13 (41)
2022-09-14T03:35:26.557696823Z Warning: PV: Kd6 Rd3+ Ke6 Re3+ Kd7 Qd5+ Kc8 Re8# c8b8
2022-09-14T03:35:26.754645336Z Warning: Illegal PV move c8d7 from StockNemo-C65102A3 (40)
2022-09-14T03:35:26.754734313Z Warning: PV: Qf4+ Ke6 Re3+ Kd7 Qd4+ Kc8 Re8# c8d7
2022-09-14T03:35:27.695710477Z Warning: Illegal PV move c8c7 from StockNemo-050F4C13 (41)
2022-09-14T03:35:27.695791910Z Warning: PV: Kc8 Qe8# c8c7