I have sense found the solution to the problem. It is impossible to set roll and fix this issues if the input to the algorithms is just two positions. You must pass in two positions and a forward vector. I would strongly recommend to use this anytime over the built in FindLookAtRotation, as its just better.
The solution i found here c++ - How can I create the equivalent of Unity LookAt in Unreal blueprint? - Stack Overflow
I will repost the solution incase the link dies
FRotator MyLookRotation(FVector lookAt, FVector upDirection)
{
FVector forward = lookAt - GetActorLocation();
FVector up = upDirection;
forward = forward.GetSafeNormal();
up = up - (forward * FVector::DotProduct(up, forward));
up = up.GetSafeNormal();
///////////////////////
FVector vector = forward.GetSafeNormal();
FVector vector2 = FVector::CrossProduct(up, vector);
FVector vector3 = FVector::CrossProduct(vector, vector2);
float m00 = vector.X;
float m01 = vector.Y;
float m02 = vector.Z;
float m10 = vector2.X;
float m11 = vector2.Y;
float m12 = vector2.Z;
float m20 = vector3.X;
float m21 = vector3.Y;
float m22 = vector3.Z;
float num8 = (m00 + m11) + m22;
FQuat quaternion = FQuat();
if (num8 > 0.0f)
{
float num = (float)FMath::Sqrt(num8 + 1.0f);
quaternion.W = num * 0.5f;
num = 0.5f / num;
quaternion.X = (m12 - m21) * num;
quaternion.Y = (m20 - m02) * num;
quaternion.Z = (m01 - m10) * num;
return FRotator(quaternion);
}
if ((m00 >= m11) && (m00 >= m22))
{
float num7 = (float)FMath::Sqrt(((1.0f + m00) - m11) - m22);
float num4 = 0.5f / num7;
quaternion.X = 0.5f * num7;
quaternion.Y = (m01 + m10) * num4;
quaternion.Z = (m02 + m20) * num4;
quaternion.W = (m12 - m21) * num4;
return FRotator(quaternion);
}
if (m11 > m22)
{
float num6 = (float)FMath::Sqrt(((1.0f + m11) - m00) - m22);
float num3 = 0.5f / num6;
quaternion.X = (m10 + m01) * num3;
quaternion.Y = 0.5f * num6;
quaternion.Z = (m21 + m12) * num3;
quaternion.W = (m20 - m02) * num3;
return FRotator(quaternion);
}
float num5 = (float)FMath::Sqrt(((1.0f + m22) - m00) - m11);
float num2 = 0.5f / num5;
quaternion.X = (m20 + m02) * num2;
quaternion.Y = (m21 + m12) * num2;
quaternion.Z = 0.5f * num5;
quaternion.W = (m01 - m10) * num2;
return FRotator(quaternion);
}
