Your mesh likely just has over 20,000 triangles and is getting decimated/simplified automatically. The Import 3D window usually shows a small warning symbol to indicate that it has occurred, which is why I asked you to send a screenshot of it.
Your mesh likely just has over 20,000 triangles and is getting decimated/simplified automatically. The Import 3D window usually shows a small warning symbol to indicate that it has occurred, which is why I asked you to send a screenshot of it.