Hi,
that is weird. I replayed using the MessChess Chess-Master (set 1=chessmst) using level 4 (3 min/move) and starting from the position after 82...Qd7 (repeated position in the above game), and this is the outcome:
[Event "Computer chess game"]
[Site "Arena"]
[Date "2025.09.01"]
[Round "?"]
[White "Opponent"]
[Black "MC VEB Chess-Master"]
[Result "0-1"]
[BlackElo "1215"]
[Time "07:54:57"]
[TimeControl "40/600:40/600:40/600"]
[SetUp "1"]
[FEN "1K6/3q4/8/8/2p5/2k5/8/8 w - - 0 1"]
[Termination "normal"]
[PlyCount "8"]
[WhiteType "human"]
[BlackType "program"]
1. Ka8 Kb4 2. Kb8 Ka5 3. Ka8 Kb6 4. Kb8 Qe8# 0-1
MfG,
Eric