Why do some objects freeze on creation?

After being instantiated, a few different types of GameObjects freeze at (0, 0, 0). After 10 seconds, they can be moved, and fall to the ground (They have rigidbodys and box colliders). Other types work fine. When it is frozen, if I change the position through the inspector, then when I unpause it, it snaps back to (0,0,0). If I put an object somewhere from the start of the game, the problem still occurs. I cannot find anything that differentiates the three types of objects for which this happens from the others.

The objects have animations with positional information attached. This is common when importing directly from a, say, FBX file.

If they’re not supposed to animate at all, I’d recommend just using the mesh from the import file, rather than pulling a whole object from it. If they are supposed to animate, it is easiest to just child them to empty GameObjects and move the empties around.