When Vector3.down doesn't go down

I have this code that was working on a sphere
transform.Translate(Vector3.down * fallSpeed * Time.deltaTime);

When I added it to a AI model it now thinks down is the direction it is facing. Is there a way to reset the axis or something on the model so Vector3.down is actually down. I have tried up, left and right but they go all the other directions except the one I want

It’s worth a look at how the Translate method in Transform works. The documentation can be found here:

By default, when you perform a translation like this then it will be done in the object’s own space (Space.Self), so if its coordinate system isn’t rotated to match the world’s then you will see behaviours of the kind that you have described. Since you want the object to use the world’s system, there are a few things you can do:

transform.Translate(Vector3.down * fallSpeed * Time.deltaTime, Space.World); // Most like your current solution.

// Or

transform.position += Vector3.down * fallSpeed * Time.deltaTime; // Already in world space.

Or you could work with rigid bodies and let the physics engine take care of things. I assume there is a reason for not wanting that though.