Blame the odd non-IEEE-754 floating point implementation changing physics enough that AI fails most of the missions which softblocks progress quite egregiously
Made me laugh though, when in the first level that it completely blocks, the director tells you to get close to a pickup, but the car you're chasing smashes the pickup to the sky like Team Rocket.
Last I heard there was a feature branch for testing a software implementation of floating point that would fix these issues, but naturally it would be a lot slower. I haven't tried it myself.
Blame the odd non-IEEE-754 floating point implementation changing physics enough that AI fails most of the missions which softblocks progress quite egregiously