Why does my vehicle disappear after location "x" reaches 1047709

I am making an endless racing game. My vehicle disappear after playing for sometime. I tried to debug it, what i found was after the location “x” of the vehicle reaches 1047709. the vehicle disappear.

You cannot go that far, well, you can but it does not work well as you can see.

1m units is what, 10km in one direction? You should not go beyond an area that is 5km x 5km, so 2.5km in one direction?

Physics becomes unreliable due to floating point errors (around half a million uu if I remember correctly)

Use World Origin Shifting for endless type of games. This will recenter the world.

You can also look into World Composition