Family Sharing calendar not working

We set up Family Sharing, and automatically a Family Calendar for everyone in the Family Sharing Group appeared in their calendar list, but when anyone in the group adds something to that Family Calendar it doesn't show up for anyone else in the family group. Yes, we are making sure it's being added to the Family Calendar, and we all have our Calendar apps using iCloud. What's wrong? Reached out to support, and all they could say was to start sharing calendars with each other, but that is something completely separate - the ability to share calendars with others, outside of your Family Sharing group, and even if you don't have Family Sharing set up. Does this mean that the Family Calendar in Family Sharing is defunct? Do we have to share the Family Calendar with each other, same as we'd share with people outside of the Family Group in order for it to work?