Shared sub-calendars appear as a folder to recipients

Shared sub-calendars appear as a folder to recipients. 

Steps to reproduce:
1. Share new calendar to a user.
2. User accepts calendar share.
3. Create a new sub-calendar.
4. User receives sub-calendar as a folder instead of a calendar. The
sub-calendar is of a folder type instead of a calendar type.

Workaround steps (the recipient):
1. Open the properties of the sub-calendar
2. General tab | Select Calendar Folder
3. Display tab | Select from the "Settings name" dropdown "Calendar Items"