ab6nix wrote: no, the camera is just falling down continuously, like no ground.
OK, I get it now.
So you are moving in a direction and that direction suddenly changes into vertical.
There are two possibilities:
1. You accidentally pushed the keyboard shortcut for going downward. This is the C key by default in the INT version which is very close to the WASD keys used for navigation. The reason I think this may be the case is because in the video the camera was moving downward at your first attempt, but not moving at the second.
2. It is really a bug. If you think that is the case you should report it to your local reseller.
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