Why do you set glass IOR as water IOR?
It was an accident, after much experimentation, I checked the effect of the change in IOR large windows on the total render time )
I also noticed a strange thing, when the background is made self-illuminated material does not emit light, it is visible only in the line of sight, and only the environment reflections (Corona sky), and when I turn on the light emission mode, it then appears in the reflections. For this reason, I began to use a conventional corona material with self-illumination and diffuse level 0, putting it in Ray switcher reflection / refraction / direct. As such, the background is reflected in all objects and can be seen in the line of sight. Faced someone similar?