When a vehicle's wheels are destroyed, the corpses of its crews, will be dropped by the player, or other ai-unit underground.
Video example 1 here - https://youtu.be/x01ZMOvCC6k
Video example 2 here - https://youtu.be/iG6vaspJBLQ
Video example 3 here - https://youtu.be/9M7TQ9nCPEE
Video example 4 here - https://youtu.be/6nSK91F9GQs
I suspect that, without wheels the root point (relative to which the spawn of the dead takes place) of the destroyed vehicle goes down,
for the this reason, the crew corpses will be spawned underground.
Please raise higher (taking into account the destroyed wheels) the spawn point for dead crews