Do you mean by "Shared iCloud" the Shared albums? Then it is intentional. Photos is stripping metadata, when we share a photo in a shared album for privacy reasons.
See the footnote here: How to use Shared Albums in Photos on your iPhone, iPad and Mac – Apple Support (UK)
"Shared Albums upload a copy of your data. Downloaded content may not contain the same information as the original."
Sometimes it is not wise to include the location, for example, if you do not want to share the address where you are living, or if you have taken nature photos of protected species you should not share the exact location where the protected animals can be found. Rather than providing a tool to remove locations selectively, Apple is removing all locations by default.
To share locations and titles add this information as a comment, when you share a photo in the shared album.
When you are sharing the photos in a Shared iCloud Photos lIbrary, the metadata will be saved and the photos will be shared in the full quality, not downsized, as in Shared albums.
The storage is used only once, and counts against the storage subscription of the person who is setting up the Shared iCloud Photos Library: How to use iCloud Shared Photo Library – Apple Support (UK)