Substrate Glass shader not working

Any Substrate wizards here? Struggling trying to get a proper glass shader working. Simple scene. Wine glass mesh with HDR Backdrop and a directional light. In the rendered image are 2 glasses. On the left using the default Uber Glass material from this pack

https://www.fab.com/listings/54ad872f-6fd5-4dc2-876b-37c0790a42c9

On the right a simple bare bones glass material (attached and circled green in image)

Both are incorrect! In particular the HDR Backdrop is not visible in parts of the glass (circled pink) Lumen, Deferred with highest quality settings.