Hi @Aaron342 I hope you are well!
The "team" and "co-host" functions apparently don't work well together- if you have team enabled on your account you won't be able to add new co-hosts and so on, so be careful with that! The reason you can't get your co-hosted listings onto your team calendar is because the ones you co-host aren't technically yours to add to a team, but the listing admin/owner.
The listing admin could create a team and add the people you need, but then that defeats the point of having a co-host as the listing admin then begins having to manage permissions etc!
Paul 🙂