Here's an excellent video illustrating why we should all be using Principled BSDF for Glass, at least when it comes to realistic glass refractions in Eevee.

Perhaps this bug has been corrected with the Glass BSDF shader in most recent builds, but I don't see any mention of it in the updates. If anyone finds this issue being addressed, please let me know. Otherwise, it's probably a good idea to stick with Principled shader when recreating glass in Eevee.

Thanks for the share LuxXeon

Thanks for this.. . Glass and Reflections seem to be a pain in blender.

mmoir posted at 9:03PM Thu, 28 January 2021 - #4411319

Thanks for this.. . Glass and Reflections seem to be a pain in blender.

This is only for Eevee rendering. In Cycles, glass and reflections just work. Eevee doesn't use path tracing for reflections or refractions, that's why certain materials like glass need special care to render realistically. Of course, the result can look almost as good as Cycles renders but cost almost nothing in terms of time, so the extra setup is usually well worth it, especially for animation.

If you use Cycles for rendering, you don't have to worry about any of this. Glossy and metallic materials will reflect the environment and each other as expected, and refractive materials will work as expected too. No different than most other path tracing render engines. The tradeoff, of course, is speed. You will need a very good processor and/or a very high-end GPU with RTX Optix technology to get render speed anywhere near Eevee. Of course the results will almost always look better with Cycles, but render times will reflect that quality.