Which version of Grip were you using :
When does this happen : A section of the track approx. halfway round where the track splits into two.
On which track did it happen : Skytrack (specific to this track)
On which speed did that happen (if related to physics) : All
How often does this happen : Whenever you fall off the track at that section
How to replicate the steps (if reproducible) : Fall off the track just after the ramp
More details :
There is The right hand side continues on whereas the left hand side has a ramp to a section of track that is upside down. Falling off this section of track respawns you back in front of the ramp, but too close. Both player cars and those driven by the CPUs are unable to get enough speed to hit the upside down section of track and fall down again, creating a repeating loop.
Users can just slow down and reverse to the right hand track, but CPU cars will continue to fall/die/respawn continually. Should be a quick fix, the spawn point just needs moving back.