Offset transform.forward by 45 degrees down

Hello, I would like to shoot a ray forward, at an angle downward, from an object. I’ve tried the following code, but it just tilts the ray very slightly to the side. Any ideas what I can do? The ray must be at the same angle from the object, regardless of which way up it is.

Debug.DrawRay(transform.position, Quaternion.Euler(45f, 0, 0f) * transform.forward)

you can use (transform.forward + transform.down).normalized to get a vector pointing 45° down. This uses the down vector from the objects point of view.
If the transform is tilted, then the vector will also be tilted.

I tried the code and it works for me, even with non-uniform scaled transforms…

Is it possible that you have set Gizmos.matrix prior to this draw? If so, just reset it to Matrix4x4.identity, otherwise no clue.