Hey Ric , this issue has been shared with us before. Allow me to copy my answer to the user, from which I have unfortunately not heard back yet:
Is there a chance you could transfer the project over? If so, I'll provide you with an upload link. It's a bit peculiar especially that this behavior only occurs on some part of the glass. If sending over the project is impossible, can you then also send us a feedback report (!!! with a link to this thread in the submission form for context/reference !!!), plus, can you send me a screenshot of the appearance tab settings of your glass in the Revit material editor? Thank you!
I'll send a feedback report with reference to this thread.