Steps to reproduce:
1. Create a new file using Model template.
2. Menu -> Tools -> Customize.
3. Commands (tab) -> New Item -> Drag the 'New Group' and drop it to Ribbon
4. Drag and drop some commands to this group.
5. Click on the chevron/triangle on this group.
Note that commands are not shown in the group.
This is expected behavior. "New Group" is a custom user created group.
Custom containers do not have the concept of turning on and off visibility of
the command temporarily. This is because there is no baseline for which to
return. Commands can only be added or removed.
Notes and References
OS Version: n/a