It’s similar to how an LLM can sometimes play chess on a reasonably high (but not world-class) level, while Stockfish (the chess solver) can easily crush even the best human player in the world.
To limit the scope of what it has to simulate.
It's unlikely they're perfect, but there's very small differences in EV betting 100% vs 101.6% or whatever.
Stockfish isn't really a solver it's a neural net based engine
Your 72o comment indicates you are either playing with very weak players, or have gotten lucky, as in reasonably competitive games playing (and then full bluffing) 72o will be significantly negative EV. Try grinding that strategy at a public 10/20 table and you will be quickly butchered and sent back to the ATM.