I have a model group which appears in several instances in the project.
When I hover over the group, a strange empty volume appears inside the group and extending slightly over the top of it.
When i tab select onto this shape, it only tells me that it's a shape handle.
When i try to restore excluded members, Revit is unable to restore all excluded members and to check the nested subgroups.
I have tried ungrouping and editing the group but neither method reveals any weird or extra geometry that could produce what i'm seeing.

Here is the warning when I try to exclude:

Any ideas to troubleshoot?
Thank you
Revit is amazing