Unrelated axis increasing after player rotates

I am trying to build a grid based dungeon crawler and I'm running into a problem wherein after rotation transform.forward increases both the x and z axis values. Despite this the player does not move towards the z axis but the collision detection thinks it does, stopping movement.

public void RotateLeft()
{
    if (AtRest) targetRotation -= transform.up * 90f;
}
public void RotateRight()
{
    if (AtRest) targetRotation += transform.up * 90f;
}
public void MoveForward()
{
    if (CanMove(Vector3.forward))
    {
        if (AtRest) targetGridPos += transform.forward;
    }
}
public void MoveBackward()
{
    if (CanMove(-Vector3.forward))
    {
        if (AtRest) targetGridPos -= transform.forward;
    }
}
public void MoveLeft()
{
    if (CanMove(-Vector3.right))
    {
        if (AtRest) targetGridPos -= transform.right;
    }
}
public void MoveRight()
{
    if (CanMove(Vector3.right))
    {
        if (AtRest) targetGridPos += transform.right;
    }
}

bool CanMove(Vector3 direction)
{
    if (direction.z != 0)
    {
        if (Physics.Raycast(zAxisOriginA, direction, rayLength)) return false;            
        if (Physics.Raycast(zAxisOriginB, direction, rayLength)) return false;
    }
    else if (direction.x != 0)
    {
        if (Physics.Raycast(xAxisOriginA, direction, rayLength)) return false;
        if (Physics.Raycast(xAxisOriginB, direction, rayLength)) return false;
    }
    return true;
}



bool AtRest
{
    get {
        if((Vector3.Distance(transform.position, targetGridPos) < 0.05f) && 
            (Vector3.Distance(transform.eulerAngles, targetRotation) < 0.05f))
            return true;
        else
        {
            return false;
        }
    }
}

From what I see, you're calling CanMove on a Vector3 direction which is absolute, then moving in the transform direction which is relative to the transform. Let's assume your player is facing to the right and there is a wall directly ahead of them. Now if the player attempts to move up (i.e. right of themselves) the collision detection function would incorrectly prevent the player from doing so despite it being a legal action. This is because Vector3.right is facing the wall, while tranform.right would be facing up. I would recommend that you always use transform directions in this case.

public void MoveForward()
{
    if (CanMove(transform.forward))
    {
        if (AtRest) targetGridPos += transform.forward;
    }
}
public void MoveBackward()
{
    if (CanMove(-transfrom.forward))
    {
        if (AtRest) targetGridPos -= transform.forward;
    }
}
public void MoveLeft()
{
    if (CanMove(-transfrom.right))
    {
        if (AtRest) targetGridPos -= transform.right;
    }
}
public void MoveRight()
{
    if (CanMove(transform.right))
    {
        if (AtRest) targetGridPos += transform.right;
    }
}