Knight and bishop mate against players

Hi everyone, I have been playing chess for a little while now and after getting a little bored of the game itself, I decided to learn the knight and bishop mate. It didn’t take long and I can now consistently beat the “master” 3200 bot in chess.com. However, I am much much less consistent playing this mate against other players, it’s embarrassing! I have tried to play worse bots because I thought the maximum bot may be too predictable. They were just as easy to beat. Is there a reason why the 3200 bot is worse than 1000 rated players in this mate or do I just need to practice? 
in any case, I think this brings up a wider discussion on how terrible bots are at mimicking humans and the ratings they’re designed to represent.

Thanks in advance,

Blunty

I thought something like that too but when I analyse endgames, stockfish is terrible at realising it’s in a loosing knight-bishop endgame, usually giving the winning player just over a three point advantage. This happens all the way up until it’s pinned against a side when it suddenly realises it’s screwed and says mate in 10 or something. I get chess is a super complicated game but stockfish on chess.com has often said something ludicrous like mate in 70 in less complicated situations, so I believe it’s capable of calculating the endgame.