If you have a group that contains (the free) Condo I/O items, duplicating the group via alt-drag will properly group the copy, but the items in the original group will no longer be grouped.
Steps to Reproduce
Create a group containing both normal furniture and a Condo I/O item (e.g. a door and a blocking volume). Then, click on the group to enable gizmos, and alt-drag one of the transformation axes to duplicate it.
What I expected to happen
The group duplicates, forming two groups.
What happened
The group duplicates, but only the new moved copy remains grouped. The items in the original group you duplicated are no longer grouped together.
Notes / Media
Probably due to issues with alt-dragging Condo I/O items, as alt-dragging an individual I/O item (or a group of I/O items) will duplicate them, but won’t move them.
Additionally, if you have a group of both Condo I/O items and normal furniture, stashing the group by right-clicking normal furniture will stash all the items, but stashing by right-clicking I/O items will only remove the I/O item.