I'm having an issue with Cycles in Blender 2.91.0.
I have Film>Transparent>Transparent Glass checked in the Render Properties Panel.
In the Render Result window I get this, which looks like it's supposed to. The glass is visible, but transparent where it needs to be.
When I save it as a PNG or view it in the Compositor, all the transparent zones are clipped out. Anything below a certain threshold of transparency just gets removed.
Thanks for looking!


However, thank you for the relevant information, I believe that has at least partially answered my question, though I'll need to investigate a bit further to be sure.
– dan_envadiv Feb 04 '21 at 03:41